Hi, Amarie!
So I went and asked my mother-in-law, who is a full-blooded Mexican, how does she make the salsa para las enchiladas.
Here's her recipe:
Salsa verde (green sauce)
6-7 green tomatoes (mid-sized)
3-4 chiles serrano (it's not a very spicy variety, I'm told, but for Mexicans, nothing really is)
1 sector of garlic (sorry, I can't get the right word for this, it eludes me)
1 onion (mid-sized)
Boil tomatoes with chile until the tomatoes change color. Mix in blender together with garlic.
On a pan, fry thin onion rings with little oil until the onions become glassy and separated. Pour tomato-chile mix onto the onions, add little water and salt and boil. Taste. If it needs something, add to your taste.
Salsa roja (red sauce):
Use Mole rojo (available in every Mexican-related market). Fry onion rings, put mole on the pan with little oil and water, boil, add salt and voila! it's ready.
I haven't made this myself and as I am allergic to chile, I probably never will, but my husband never misses a chance to eat her mother's enchiladas.
Hope this helps!