Heat a griddle or frying pan over high heat. Remove husks from tomatillos and stem the serranoes. Rinse them off. Add a thick slice of onion (I usually use white, but I think any onion will do). Peel garlic cloves.
Place all vegetables onto the griddle and roast until they are blackened – about ten minutes. Turn the veggies over so that everything is uniformly blackened. That will give the sauce a nice smoky taste.
The garlic cloves will blacken first. Using tongs, toss them into a blender or food processor. As everything else blackens, throw them in with the garlic. Don’t worry about chile and tomatillo skins, they will just add texture. As everything blackens, you can turn down the heat to medium or medium low. By the way, some recipes call for boiling the tomatillos and chiles, etc. FORGET IT! You will want that smoky taste and aroma.
Add a teaspoonful or cube of chicken bouillon and a little water for desired consistency – 1/4 of a cup.
Blend the mixture on high for a good 30 seconds or more until the chile sauce is nice and smooth. At this point you can add a small handful of chopped cilantro if you like.
Take a deep breath of the chile sauce while it’s still in the blender. If your hair stands on end, it will be just right.
Fill a glass container with the sauce and refrigerate. The sauce is just like a bottled commercial sauce, it will keep for several weeks.
Use the sauce on just about everything, from eggs to soup to meats, fish and poultry. You can also use the sauce to prepare enchiladas or if you are ambitious, tamales. Share the sauce with your children and grandchildren, your friends and neighbors. They will be SO IMPRESSED AND GRATEFUL!