Preheat oven to 400˚F.
Slice off the top of the head of garlic, exposing the cloves. You'll only use half of the cloves in the recipe, but roast the whole head and save the remaining cloves for another recipe!
Place the bell pepper (skin side up), carrots, cauliflower, tomatoes, garlic and onion to a large sheet pan. Drizzle with olive oil, then evenly sprinkle with the salt, smoked paprika, cayenne and cumin. Roast for 40-45 minutes, until all vegetables are fork tender.
About 10 minutes before the vegetables are done, add the broth to a small pan over medium heat or pop it in the microwave until it's hot.
Once the vegetables are done, immediately add to a blender. Squeeze out the garlic cloves from ½ of the head of garlic. Save the other half for another recipe. Add in the hot broth and the lemon juice and blend until smooth. Taste and add remaining ½ tsp salt if needed (this will depend on how salty your broth is and the type of salt you use).
Serve hot with grilled cheese or these grilled cheese croutons.
To make grilled cheese croutons, add butter to a pan over medium low heat. Begin toasting bread in the pan until it's golden brown and caramelized, then flip one piece over and add cheese slices to the caramelized surface. Place the other slice, cooked side down, on top of the cheese. Cover with a lid. Cook until bottom is brown and crispy, then flip again and cook until other side is brown and crispy, and cheese is completely melted. Remove from heat and slice into small cubes.