How do you make a simple green salsa?

Blend the following ingredients in a blender:
  
8 Jalapeños or 4 Serrano Peppers (your heat pref)
4 Tomatillos
½ Small Onion
1 Garlic Clove
½ Bunch of Cilantro
1 Big Avocado 

After it's blended well pour the salsa into a bowl and mix with a spoon. Next mix one lime or lemon and salt to taste. Save the pit of the Avocado and insert it into the salsa to preserve its freshness.