I'll toss my recipe in:
1 32oz (or the roughly 1 kilo medium cans if they have them out that way, otherwise two "regular size") can(s) of whole tomatoes
However many jalapenos you desire, for mild I would start with 1/2 and adjust.
1 bunch of fresh cilantro, frozen cilantro can be used if fresh isn't available. Dried is kind of a last resort but better than nothing. If fresh, chop roughly.
4-6 cloves of garlic depending on personal taste
1 lime, juiced
1 medium onion, color is not important, chopped coarsely
1/4 tsp oregano powder
salt to taste
Cut open the pepper(s), remove the seeds, chop coarsely.
Combine everything but salt in a food processor and pulse until you reach the desired consistency. At that point, test for heat and salt and adjust as needed. It is nigh on impossible to over chop this stuff so don't worry about running the processor too long, just worry about the flavor.
That's the recipe I learned from a little Mexican grandmother neighbor who taught me all sorts of great recipes. I typically do 2-3 Jalapenos and 2 lime's worth of juice since I like it extra hot.