1. Preheat your oven to 450°F (230°C). Place the red bell peppers on a baking sheet and roast for 20-25 minutes, turning occasionally, until the skins are charred.
2. Remove the peppers from the oven and place them in a bowl. Cover with plastic wrap and let them steam for 10 minutes. Peel off the skins and remove the seeds.
3. In a large pot, sauté the chopped onion and minced garlic until softened.
4. Add the roasted peppers and vegetable broth to the pot. Bring to a boil, then reduce heat and simmer for 10 minutes.
5. Use a blender to puree the soup until smooth. Return the soup to the pot and stir in the heavy cream. Season with salt and black pepper to taste.