Begin by heating the olive oil in a large non-aluminum saucepan over medium heat. Allow it to shimmer, indicating it’s ready for the next step.
Add the finely chopped onion and sauté for about 3 to 5 minutes until translucent.
Incorporate the sliced bell peppers. Stir them into the pan and cook for about 5 minutes until they start to soften.
Add the chopped tomatoes, chipotle chile, and basil. Cover partially and reduce the heat to medium-low. Let simmer for about 20 minutes.
Once cooked, remove from heat and allow to cool slightly before puréeing.
Transfer the mixture to a food processor and purée for about 1 minute until smooth but with some texture remaining.
Taste and add salt and black pepper to your liking.
Return the sauce to the pan and warm gently before serving.
Serve your delicious Red Pepper Tomato Sauce over pasta, as a dipping sauce, or with grilled vegetables.
