Place tomatoes, jalapenos, onion, and garlic on a large baking sheet and broil for 8 minutes, flip the tomatoes and jalapenos and broil 8 more minutes.
Allow vegetables to cool for about 10 minutes. Remove stems from jalapenos (leave seeds for a little heat) and skins from garlic and onion. Roughly chop the onion. Place all the vegetables, cilantro, juice, salt, and cumin in a food processor or blender. Pulse until desired chunkiness.
Place in jars and refrigerate or serve with chips or as a condiment.