Place tomatoes, jalapeños, and ½ onion on hot cast iron pan. Turn ingredients so you achieve a nice char on all sides.
When jalapeño is nicely blackened, place on a cutting board and cut off top and remove seeds.
Place charred items in the food processor. Puree everything until no large pieces remain.
Add cilantro. Pulse just until mixed.
Transfer to mixing bowl.
Stir in salt, juice of lime, and chopped green scallions.
Taste and add additional salt if needed.
Video
Notes
Tips:
Buy fresh, unblemished vegetables
Char on a hot, ungreased skillet. Don't let the vegetables burn, but just get a light black, or char on each side.
Use a food processor to help blend all the ingredients. Just pulse until it is the desired consistency. If you go too long, you'll end up with a tomato sauce.
Taste before serving and add extra salt and lime juice to taste
Store salsa covered in the refrigerator for up to 5 days