3cupsjarred roasted red peppersdrained and rinsed, coarsely chopped if whole
1⁄2 teaspoon hot red pepper flakes
5springs fresh thyme
3 & 1⁄2cupsvegetable broth
Freshly ground pepper
Heat butter in large saucepan over medium-high heat until melted. Add onion and 1⁄2 teaspoon salt and cook until the onion begins to brown, about 15 minutes. Add garlic and cook, stirring frequently, until lightly browned and fragrant, about 1 minute.
Add flour and stir until flour is lightly browned, about 1 minute. Add red peppers, red pepper flakes, thyme, broth, and water, and bring to a boil. Reduce heat, partially cover, and simmer until peppers are soft, about 20 minutes.
Remove and discard thyme sprigs. Working in batches, puree soup in blender until smooth and creamy. Return soup to pot, and heat over low, stir in milk, and adjust the seasonings to taste with salt and pepper. Serve hot.
If you want the soup to be thicker for a lasagna sauce, continue to cook, stirring frequently, for about 10 more minutes.