Preheat the oven to 400 F. Toss together the tomatoes, 1/4 cup olive oil, salt and pepper. Spread the tomatoes in 1 layer on a baking sheet and roast for 45 min.
Saute onion, garlic and red pepper flakes in 2 tbsp olive oil and butter, till slightly brown.
Add the canned tomatoes, basil, thyme and chicken broth. Add the oven roasted tomatoes including the juice. Bring to a boil and simmer uncovered for 40 min. If you like your soup smooth you can put the soup in the blender and liquefy it or use your immerse blender. Strain the soup.