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Roasted Vegetable Grilled Cheese

Fill up on savory roasted veggies with this Roasted Veggie Grilled Cheese. Stuffed with pepper, onion, and mushrooms and perfect for dipping in toasty sauce.

Three roasted vegetable grilled cheeses stacked on top of one another

Today we’re whipping up a classic lunch favorite: The Grilled Cheese. Only in this recipe, we’re giving it an upgrade and packing it with veggies and rich gouda! And to achieve that sought after crispiness, we’ll coat the outsides of the bread in a generous layer of mayonnaise. It’s the best way to achieve that golden glow!

But we’re not stopping there. While living in the Netherlands I picked up a love for toasty sauce. Gouda grilled cheeses and other panini-style sandwiches (“toasties”) are often served with “toasty sauce”, a flavorful blend of mayonnaise, BBQ sauce, and hot sauce and that serves as the perfect sidekick for this gouda panini! 

You can use any sauce you’d like, but I definitely recommend using something to offset the crispiness and add extra savory flavor. We’re sauce people around here!

Close up view of 3 stacked roasted vegetable grilled cheeses displaying the fillings of pepper, onion, mushrooms, and gouda

Here’s what you’ll need

The ingredients in this pepper and mushroom grilled cheese are exactly what you’d expect: lots of veggies and delicious sourdough (or multigrain) bread! For the grilled cheese you’ll need:

  • Red Bell Pepper: Roasted bell peppers are a must on any vegetable panini. You can use red, green, yellow, or orange!
  • Sliced Mushrooms: As far as mushrooms go, you can use brown, white, or whatever you have on hand! You’ll need 2 cups.
  • White Onion: Next up, white onion. You’ll need ½ cup, sliced.
  • Bread: Bread can make or break a grilled cheese! For best results, use 4 thick slices of either sourdough or multigrain. 
  • Gouda: You’ll need 3 slices of gouda, as we’ll be using 1½ on each sandwich. Can’t find gouda? Cheddar, jack, or muenster also work well!
  • Mayonnaise: Did you know grilled cheeses are ten times better when the outsides of the bread are coated with a layer of mayo? It helps them reach that perfect golden color!

The toasty sauce is a quick combination of mayonnaise, BBQ sauce, and optionally hot sauce. Whip it up while your grilled cheese cooks!

A plate filled with three roasted vegetable paninis, toasty sauce, and tortilla chips

How to make a roasted veggie grilled cheese

This vegetable grilled cheese is made complete in just four steps. We’ll start by roasting the veggies, then we’ll assemble and cook the sandwiches panini-style.

Step 1: Roast the vegetables
Preheat the oven to 400°F (204°C). Slice the pepper, mushrooms, and onion, and throw everything onto a large rimmed baking sheet. Drizzle with olive oil and sprinkle with salt and pepper, tossing to evenly coat. Bake for 15 minutes, or until the vegetables are soft. 

A baking sheet filled with sliced onion, mushrooms, and red bell pepper

Step 2: Prepare the toasty sauce
While the veggies cook, mix together all of the toasty sauce ingredients (mayo, BBQ sauce, and hot sauce). 

Step 3: Assemble
Build two separate sandwiches by layering 1 slice of cheese, a heap of roasted vegetables, and ½ slice of cheese atop the bread. Spread mayonnaise on the outsides of the bread. 

A 4-step image outlining the correct steps for layering the roasted vegetable grilled cheese ingredients

Step 4: Cook the sandwiches
Finally, cook the sandwiches in a skillet over medium heat, or in a panini press. Cook until the outsides are golden brown and the cheese has melted. Serve immediately with the toasty sauce for dipping. 

A plate filled with three roasted vegetable paninis, toasty sauce, and tortilla chips

Grilled cheese variations

In the mood to mix things up? Here are some ways that you can switch up your vegetable grilled cheese.

  • Swap the Pepper: Any mild pepper works well here, to include green bell pepper, poblano, or anaheim.
  • Red Onion: This recipe calls for white onion, but you can also use red! You can spice things up by using caramelized or pickled onions too.
  • Pepper Jack Cheese: Though this sandwich isn’t a gouda panini without the gouda, it would also taste great with pepper jack (or even a pepper jack and cheddar combo).
  • Sauces: Toasty sauce is the best for this sandwich, but you can use whatever you’d like! Blue cheese, ranch, and even plain hot sauce all taste great.
Three roasted vegetable grilled cheeses stacked on top of one another

More grilled cheeses and paninis to devour

Because you can never have too many jam packed loaded sandwiches, here are four more of my favorites! Each recipe presents unique flavor pairings like blueberry x balsamic and strawberry x avocado. 

Roasted Vegetable Grilled Cheese

A warm and cheesy Gouda grilled cheese with roasted red bell pepper and a sweet and savory mayonnaise toasty sauce. Perfect with tomato soup!
Print Pin Rate
Course: Main Dishes, Sandwiches and Wraps
Cuisine: American
Keyword: gouda grilled cheese
Diet: Vegetarian
Occasion: 4th of July, Game Day, Halloween
Time: 30 minutes or less, 45 minutes or less
Prep: 5 mins
Cook: 25 mins
Total: 30 mins
Servings: 2 people
Calories: 507kcal
Author: Sarah Bond
5 from 11 votes


Grilled Cheese
  • 1 red bell pepper sliced
  • 2 cups sliced mushrooms brown, white, or whatever you have on hand
  • ½ cup sliced white onion
  • 1 Tbsp olive oil 15 mL
  • Pinch salt and pepper
  • 4 thick slices bread sourdough or multigrain are best
  • 3 slices Gouda cheese
  • 2 Tbsp mayonnaise
Toasty Sauce
  • 1 Tbsp mayonnaise 15 g
  • 1 Tbsp BBQ sauce 15 g
  • Splash of hot sauce optional


  • Roast: Preheat oven to 400°F (204°C). Slice pepper, mushrooms, and onion. Throw onto a large rimmed baking sheet. Drizzle with oil and sprinkle with salt and pepper, tossing to evenly coat. Bake for 15 minutes, or until veggies are soft.
  • Sauce: Meanwhile, Mix together all Toasty Sauce ingredients.
  • Assemble: Build two sandwiches by layering 1 slice of cheese, a heap of roasted veggies, and ½ slice of cheese. Spread mayonnaise onto the outsides of the sandwich.
  • Cook: Cook over medium heat in a large skillet or panini press until outsides are golden brown and cheese has melted. Serve immediately with Toasty Sauce for dipping!


Serving: 1sandwich | Calories: 507kcal | Carbohydrates: 41.3g | Protein: 17.8g | Fat: 29.9g | Sodium: 1058mg | Fiber: 4.3g
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Recipe Rating

  1. Sarah says:

    I love the War of Art! I’m constantly having to remind myself not to fall prey to the pull of procrastination and making up excuses. Glad you’re fighting back and getting back into the things you love.

    As for the toasties….YUM! Hello, lunch!5 stars

    1. Sarah says:

      Right? Making excuses is always my downfall. Glad to hear I’m not alone! Thanks so much for stopping by, Sarah! 🙂

  2. candy says:

    Roasted peppers are one of my favorite ingredients to use. Simple and delicious.

    1. Sarah says:

      Mine too! They just instantly spruce up any dish! Roasted garlic too 🙂 Actually just anything roasted!

  3. Platter Talk says:

    Thanks for this flavorful and delicious looking grilled cheese sandwich! Love the pepper and the Gouda!5 stars

    1. Sarah says:

      You’re very welcome! Thanks for stopping by!

  4. Claudia | Gourmet Project says:

    A friend gave mea good trick: concentrate hard stuff on between tuesdays and thursday and kepp the easy and light stff for mondays and fridays. sometimes it works 🙂 but do cook! I need more of these wonderful grlled cheese recipes!5 stars

    1. Sarah says:

      Good advice! I have an agenda where I have “cooking days” and “get tedious sh*t done days” and it seems to be working well. The cooking days feel like easy days, so my head has time to clear 🙂 Thanks so much for the advice, Claudia!

  5. Rutuja Bhagwat says:

    It looks so yummy! Thanks for the recipe, especially the toasty sauce! x

    1. Sarah says:

      Thanks Rutuja! I’m not sure how I lived without toasty sauce for so many years before moving in with the tulip-man. Happy I could share it with you! 🙂

  6. Jessica Fancy says:

    Your food photography is phenomenal!5 stars

    1. Sarah says:

      Thanks so much, Jessica! 🙂

  7. linda spiker says:

    Gouda is my favorite cheese! love this recipe!5 stars

    1. Sarah says:

      Thanks Linda! I’m loving it more and more with each recipe I try 🙂 It’s just perfect in everything!

  8. kristen says:

    i LOVE grilled cheese – wow oh wow. This looks so good and with gouda!! my mouth is water! I’m pinning this for later! xx5 stars

    1. Sarah says:

      Haha thanks Kristen! Perhaps I should start cooking up more grilled cheeses 🙂 They’re just so perfect for these cold, cozy winter months. Thanks so much for sharing!

  9. Maggie Unzueta says:

    That looks incredible. Roasted pepper and gouda go so well together.5 stars

  10. Becky @ Disney in your Day says:

    This looks so good! I love grilled cheese and anything with roasted pepper is always good!

  11. Lauren says:

    I want one of these right now! This looks amazing and I pinned so I could just look at the pictures later! ha!

    1. Sarah says:

      Thanks so much for sharing, Lauren! 🙂

  12. Gloria @ Homemade & Yummy says:

    I love a good grilled cheese….and gouda works so well…nice and gooey!! The addition of roasted red peppers is perfect!!

  13. Allison - Celebrating Sweets says:

    I’ve never met a grilled cheese that I didn’t like. And toasty sauce? Very interesting. Must try!

    1. Sarah says:

      Yes you must! Toasty sauce has become quite an obsession of mine 🙂

  14. Keisha says:

    Looks great

  15. Kari says:

    I love gouda and need to make this grilled cheese soon with my favorite tomato soup!5 stars

    1. Sarah says:

      Yummm this would be so great with warm tomato soup. As I type this my toes and fingers are cold and numb so soup sounds heavenly 🙂 Thanks for dropping by, Kari!

  16. Clare Speer says:

    Looks like my kind of grilled cheese sandwich! I love love roasted peppers – being Italian American from the northeast – we love roasted peppers! Thanks for sharing this!

  17. Tara says:

    Yes, that’s just like me. If I work really hard to meet a deadline, I tend to veg for hours and hours the next day. I thought it was just me too. Gouda is my favorite for a grilled cheese, and that toasty sauce sounds pretty divine. Thanks.

    1. Sarah says:

      Glad to hear I’m not alone then! But nothing a little self-talk and grilled cheese can’t fix 😉

  18. Miss Angie says:

    This looks pretty darn good, and I’d really like to eat that.5 stars

  19. Roxy says:

    This is the best looking grilled cheese I’ve ever seen!1

  20. Ana De- Jesus says:

    What a divine recipe are you a vegetarian? I love roasted pepper with cheese so delectable.

    1. Sarah says:

      For the most part I am! Roasted pepper is one of my most favorite flavors, so smoky and savory and just perfect with everything!

  21. TJ says:

    Thank you for these vegetarian recipes. After recovering from Covid, surprisingly, 2 of my co-workers independantly decided to go vegetarian. Your chickpea recipes and these sandwich recipes are making it easier for us to fix food at work that the meat eaters can add sliced turkey/chicken to while the vegetarian guys and I can eat it with out. We work 12 hour rotating shifts in a plant and have a full kitchen. Due to the latest hurricane, some of the people from the Lafayette area had to stay here. It was great to have something a bit new and fresh to eat for lunch. Swet Baby Ray’s Barbecue sauce made it awesome!5 stars

    1. Sarah says:

      YAY! I’m so happy to hear these recipes are helping you and your coworkers out through all this turbulence. There’s a new one you all will probably like, give this “Tuna” Salad a go, super easy!