Directions

1. Cut tomatoes lengthwise and slice onion.

2. On a cookie sheet, place onion slices and tomatoes cut side down. Set oven to broil. Roast until black on the edges.

3. Over medium heat, sauté garlic in 1 tablespoon of olive oil, turning several times with tongs, for 3 minutes. Add chiles to garlic, sauté for 1-2 minutes, flipping occasionally until they just start to toast. Take care not to burn. Feel free to remove any piece of garlic or chile once browned.

4. Transfer chiles and garlic to a blender of food processor. Pour in the water and vinegar, and let stand for 5 minutes to soften.

5. Purée on high, 10 to 20 seconds. Turn to low speed and slowly add remaining olive oil. Adding olive oil slowly ensures the mixture will emulsify, creating desired creamy consistency.

6. Add the tomatoes and onion. Purée on high, until smooth.