Roast the vegetables: Preheat your oven to 400.° Arrange the chopped tomatoes, onion, red bell pepper, and garlic cloves on a baking sheet. Drizzle with olive oil and season lightly with salt and pepper. Toss everything well to coat.
Bake: Roast for about 40-50 minutes, or until the tomatoes and onions are tender and slightly charred on the edges.
Add seasoning: Once the veggies are done roasting, transfer them to a large pot. Add the rosemary, thyme, basil, and red chili flakes. Stir everything together to let the herbs warm up and release their aroma.
Blend the soup: Pour in the chicken stock and use an immersion blender to puree until smooth. (Alternatively, transfer to a blender in batches and blend until creamy, then return to the pot.)
Make it creamy: Stir in the Boursin cheese and heavy cream. Simmer over medium-low heat for 10 minutes, stirring occasionally until everything is well combined and velvety smooth.
Taste and adjust: Add more salt, pepper, or herbs if needed. If you prefer a thinner consistency, add a bit more stock or cream.
Serve: Ladle into bowls and top with a drizzle of olive oil, fresh basil, or cracked black pepper. Serve with a grilled cheese sandwich for the perfect pairing!