Here's a recipe for canning roasted green tomatillo salsa:
5 1/2 cup husked, washed, fire-roasted, and chopped tomatillos
1 cup chopped onion
I cup chopped peppers (I used 1/4 serranos and 3/4 Hungarian yellow- and I did not seed, I like it spicy)
3 cloves garlic, minced finely
1/2 cup white vinegar
4 tbs. lemon juice
2 tsp. ground cumin
1/2 tsp salt
I fire roasted the tomatillos on the BBQ a bit. I food processed the onions super-fine then measured out, and then did the same with the peppers and tomatillos. Combine everything in a pot and boil for 10 minutes. Ladle everything into your hot sterilized jars and allow 1/2" head space. Process in a water bath for 15 minutes.