Tomatoes, quartered, a shitload (I prefer roma because they are cheap and not as juicy)
Jalapeno peppers, about half the amount of tomatoes, seeded (unless you like to burn your mouth out...then, by all means, don't seed them)
Onions, peeled and quartered (about 1/2 the amount of jalapenos)
Garlic, peeled (half the amount of the onions)
Cilantro (several gigantic handfuls)
juice of a couple limes
salt (to taste)
cumin (to taste-don't go overboard-you want a HINT of cumin...not enough to identify the flavor)
Toss tomatoes, onions, jalapenos, and garlic into a pan and bake at 400 degrees until vegetables begin to brown slightly. Remove and cool.
When veggies have cooled throw everything into a food processor and puree until smooth.