There are lots of tomatillo salsa verde recipes, but they are almost all simple and easy to prepare.
Salsa Verde (basic ingredients)
2 lbs tomatillos (~5.5 cups chopped)
vinegar and/or lime juice
optional spices: salt, cilantro, cumin, cayenne, pepper, etc.
Start with a pound or two of tomatillos, peel the papery husk and rinse. The jalapenos can be cored or used whole. Coarsely chop onion. Garlic cloves should be peeled but can be left whole. I like to saute it all together in a deep pan with some olive oil, until the tomatillos just start to crack and the onions, garlic and peppers are starting to brown. Another option is to roast the ingredients in the oven. Let everything cool slightly and put it all in the food processor with your chosen spices and 1/4 cup vinegar and/or lime juice. If you are short on time, salsa verde can also be made with raw veggies but has a slightly different flavor and is best after being allowed to meld for several hours.