If you ask me, this is one of the world's greatest sauces. It provides an incredible foil for anything rich and savory—meat and eggs are uplifted to dizzying heights by its sweet+tart+spicy flavors. The list of ingredients is short and the method is simple, so the complexity of the result is rather miraculous.
This amount takes me about a week to get through if I'm just feeding myself by using it to top other dishes with. On the other hand, I've served the entire results of this recipe to three guests with chips and had it vanish in ten minutes between the four of us, so plan accordingly if you're making this for a party or something.
Now comes the time to combine everything. I prefer to grind the sauce by hand, because it stays chunky and the ingredients release their juices very well. If you don't have a molcajete or a large stone mortar and pestle, but you have an immersion blender, use that. If you lack both, use a regular blender. If you're pressed for time, the regular blender is fastest.
If using a molcajete or mortar and pestle: Cut the tomatillos into quarters. Place the two garlic cloves in the bowl along with a pinch of salt and grind to a paste, then add the peppers and grind to incorporate. Add the tomatillos, a few quarters at a time, and grind until there are only small chunks of tomatillo and the sauce is well-mixed. Stir in the cilantro and add salt and pepper to taste.
If using an immersion blender:: Place the garlic, peppers, and tomatillos in a flat-walled saucepan along with a pinch or two of salt and blend until there are only small chunks. Stir in the cilantro and add salt and pepper to taste.
If using a regular blender: Place the garlic, peppers, and tomatillos in the blender and incorporate with short, slow, gentle pulses. Stir regularly with a spatula and stop when the sauce has only small chunks. Stir in the cilantro and add salt and pepper to taste.
Now you can spoon this sauce onto just about anything rich and savory and it will taste amazing. If you want to eat a dish that really puts it in the spotlight, cook two eggs over-easy in butter and eat them topped with this sauce along with a couple slices of crusty lightly-toasted bread. Use the toast to mop up the yolk and juices once you're finished with the eggs. Simple and heavenly.