Have you experienced the unique, caramelized sweetness of baked onions yet? This understated recipe packs a ton of flavors into one simple side dish. Plus, it’s incredibly versatile, making it an unbeatable companion to a wide array of mains!
Easy baked onions
If you’ve never had the pleasure of tasting baked onions, let me assure you, you’re in for an absolute treat! Preparing baked onions is not only effortless, but the flavors they bring to the table are nothing short of phenomenal (I’m not being dramatic, I swear).
You can transform the humble onion into a sweet, caramelized, almost creamy side dish in as little as 30 minutes. It’s great for pairing with other sides like Mediterranean roasted vegetables and roasted broccoli with lemon.
Whether you have a bagful of onions or just a few leftovers from last night’s dinner prep, this recipe will help you achieve that perfect balance of flavor and crisp, caramelized goodness each and every time. Trust me, once you’ve tried baked onions, there’s no going back!
Roasted Onion Ingredients
Baked onions require very little in the ingredient department. Here’s what you’ll need:
- Onions: You can use any variety of onions, but red and sweet white onions work particularly well due to their natural sweetness.
- Olive oil: Helps the onions caramelize and enhances their sweet flavor. You can also use another high-heat oil, like avocado or grapeseed oil.
- Salt: Enhances the natural flavors of the onions. You can add some cracked black pepper for a slight kick. Alternatively, try a smoked or herb-infused sea salt for a twist.
- Herbs: To add more flavor, feel free to experiment with fresh or dried herbs like rosemary, thyme, or oregano. Aim to add hardy herbs before cooking, and tender herbs after cooking (grab our guide to types of herbs here 👈) (or, leave them out for a simple recipe!)
Which onion is best?
Each type of onion brings its unique flavor and characteristics to roasted dishes. The choice of onion can be based on personal preference (or what you have on hand).
- White onions have a mild and slightly sweet flavor. When roasted, they develop a soft and delicate texture with a subtle caramelized sweetness.
- Yellow onions are the most commonly used onions for roasting. They have a stronger and more robust flavor compared to white onions. When roasted, they become sweeter and develop a rich caramelized flavor, adding depth and complexity to dishes.
- Red onions have a milder and slightly sweet taste with a hint of spiciness. When roasted, they retain their vibrant purple color and develop a sweeter, mellow flavor.
This large nonstick sheet pan is one of my everyday favorites!
How to make baked onions
It couldn’t be easier to make baked onions! Just follow these steps.
Step 1: Slice
Start by preheating your oven to 400°F. Peel and slice your onions in half (or into about 1-inch thick coins), then arrange them on a baking sheet or casserole dish in a single layer.
Step 2: Season
Brush the onions with olive oil, ensuring all surfaces are lightly coated. Sprinkle them with salt, pepper, and any optional herbs you’d like to use.
Step 3: Bake
Bake the onions in the preheated oven for about 40 to 45 minutes, or until they are tender and nicely caramelized. Serve them with fresh herbs sprinkled on top.
These are the most essential tips to perfect this seemingly simple yet ultra-flavorful recipe:
- Similar size: For the best results, try to use onions that are all about the same size. This ensures they bake to the same tenderness.
- Season: Salt is your friend here. It helps draw out the natural sweetness of the onions, so don’t be afraid to be generous.
- Don’t overcrowd: Avoid crowding the onions on your baking tray so they achieve that beautifully caramelized exterior. Keeping them too close will result in a steam texture.
- Be patient: Give the onions time in the oven. You’ll be rewarded with baked onions that are soft, sweet, and extra caramelized.
How to store baked onions
If you find yourself with leftover baked onions, follow these simple steps:
- Fridge: Store leftover baked onions in an airtight container for up to 5 days in the fridge.
- Freezer: Baked onions can be frozen for up to 3 months. Just let them cool completely, then transfer them to an airtight or freezer-safe container.
- Reheating: Reheat your onions in the oven at 350F until warmed through, or quickly sauté them in a pan.
What to serve with baked onions
If you’re unsure of what to eat with your baked onions, fear not! Here are a few ideas to get you started:
- A hearty mushroom meatloaf
- A side of cauliflower fried rice or brown rice
- A tomato cucumber avocado salad
- Your favorite plant-based protein, like tofu or tempeh
- A piece of vegan garlic bread to soak up the flavorful onion juices
Baked onions FAQs
Yes, you absolutely can! Each type of onion brings a unique flavor and sweetness to the dish. Yellow and white onions are often the standard for their balanced taste, I really love red onions for their color and sharper flavor.
You’ll know the onions are perfectly baked when you see a golden-brown outside and they’re tender when pierced with a fork. Depending on the size of the onions, this should take about 45-60 minutes. Just make sure to check on them regularly so they don’t burn.
Yes, you can prepare baked onions ahead of time. They can be cut in advance, then stored in an airtight container in the fridge until you’re ready to bake.
- 4 medium onions red, white, or yellow
- 4 Tbsp olive oil 60 mL
- salt and pepper to taste
- herbs rosemary, thyme, parsley, etc.
- Prep Oven: Preheat the oven to 400°F (204°C) and line a baking pan with aluminum foil.
- Prep Onions: Slice off each end of the onions. Cut the onions in half or quarters crosswise. Peel off the outer layers of the onions. Arrange the onions in a single layer on the prepared baking sheet. The onions should fit comfortably without being crowded.
- Season: Brush each onion half with olive oil. You can use a brush or your fingers to ensure the oil covers the entire onion surface. Brush each onion half with olive oil. Season the onions generously with salt (and pepper if you'd like). If you're using herbs, sprinkle them over the onions now.
- Bake: Bake the onions for 40 to 45 minutes, or until they're tender and caramelized. Once done, remove the onions from the oven and let them cool for a few minutes before serving.