Brush several cookie sheets with oil and cut the tomatoes in half. Place the tomatoes cut side down and broil until charred, about 15-20 minutes.
Remove tomatoes from the oven and let cool for several minutes. Pinch off the skins and discard.
Add tomatoes, onions, jalapenos, green chili, cilantro and garlic to the food processor. You may need to work in batches depending on the size of your food processor. Puree the ingredients until smooth.
Once fully pureed, stir in the lime juice, cumin, cayenne and salt.