Step 1

Heat oil in a large saucepan over medium-high heat. Add onion, chile peppers, habaneros to taste and garlic and cook, stirring, until the onion is soft and beginning to brown, 3 to 4 minutes.

Step 2

Reduce heat to medium. Add tomatoes, vinegar, salt and sugar to taste. Cook, stirring occasionally, until the tomatoes begin to break down, about 5 minutes.

Step 3

Carefully transfer the tomato mixture to a food processor or blender. Puree until smooth. (Use caution when pureeing hot ingredients.) Set a fine-mesh sieve over a medium bowl; pour the pureed mixture through the sieve, pushing on the solids with a wooden spoon to extract all the liquid. (Discard solids.) Let the sauce cool to room temperature, about 1 1/2 hours.