Roast: Preheat oven to 450°F (232°C). Halve and deseed the red bell pepper. Place facedown on a parchment-lined baking sheet and roast for 25 minutes, until skin is a bit blackened. Add tomatoes to the sheet when there are 10 minutes left.
Cauliflower: Using a box grater, grate cauliflower into "rice". Microwave for 1 minute, or until soft. Mix in lemon juice and salt.
Prep Fillings: Measure and prep all remaining Bowl ingredients.
Sauce: Peel skin from the roasted pepper and add the pepper to a food processor or blender with 1 cup of the roasted tomatoes and all other Romesco Sauce ingredients. Blend until smooth.
Serve: Divide cauliflower rice and veggies evenly into serving bowls, topping with remaining 1 cup of roasted tomatoes and drizzling with Romesco Sauce.