Peel the outer papery husks off of the tomatillos and rinse them well. Tomatillos have a sticky, waxy skin with sticky residue - this is normal.
Cut the tomatillos in half and place them cut-side down on a baking sheet.
Turn your oven on the high Broil setting, and place the tomatillos in the oven on the 3rd shelf from the top (you want it close to the top heating element but not too close).
Broil for 6 to 8 minutes, or until the tomatillos have blackened a bit and the liquid is seeping out.
Use tongs to transfer the tomatillos to a high powered blender or food processor, along with the rest of the ingredients for the salsa.
Blend until everything is well-combined.
Use immediately or store in an airtight container or jar in the refrigerator for up to 2 weeks (note: you can store the salsa much longer if you go through the full canning process using sterilized jars, etc.)
Notes
*Use mild or hot chilis according to your spice preference. You can also replace the chilis with 2 roasted jalapenos.