Remove husks from tomatillos and discard husks. Run tomatillos under cold water and give a good rinse to remove some of the sticky exteriors. Dry completely.

Set a skillet, preferably cast iron, on high heat. Allow pan to heat for 3 minutes. Add the tomatillos, chiles, and garlic. Get a good char on each side, rotating and turning tomatillos and chiles as needed. Remove garlic once it has charred and set aside. This process will take about 10 to 15 minutes, depending on how hot you can get your skillet.

Once charred, slice your jalapeno half lengthwise and remove the vein and seeds; cut the vein with seeds attached into thirds and set it aside. Add your tomatillos, serrano, jalapeno without the vein, and garlic into your food processor pulse until combined. Add the vein and seeds one piece at a time, tasting as you go along for perfect spice. Place salsa in a medium-sized bowl. Add the red onion, cilantro, lime juice, and salt. You may need to add more salt or lime juice to taste.

If you want a thinner salsa, add filtered water one teaspoon at a time until you get desired consistency.‍