my "on the fly" salsa uses a can of tomatoes, but I don't see why you couldn't use fresh:
1 can stewed tomatoes
assorted chiles ( I used 2 serranos 2 yellow chiles, and 1 jalapeno - next time I'll use more)
1 small white onion
1/2 bunch cilantro
lots of garlic (6+ cloves)
pinch of kosher salt
roast chiles over flame or in frying pan if you like
dump everything into a VitaMix or food processor and puree until blended.
DH doesn't like citrusy salsas so he really liked this one...