2. Heat the olive oil in a saucepan over low heat. Add the carrots, celery and onions, season lightly with salt and pepper, and cook for 10 minutes.
3. Peel and slice the potato and add it to the pot. Add the bay leaf and stock and bring to a boil quickly over high heat.
4. Lower the heat and simmer until the vegetables are completely tender, about 15 minutes.
5. Add the roasted red peppers and simmer 10 minutes more.
6. Remove the bay leaf and puree in a blender. Adjust the salt and pepper to taste.
7. Chop the basil at the last minute to prevent discoloration. Serve the soup in warm bowls and sprinkle with chopped basil.