1 jalapeno**, stem removed (before or after roasting)
1/2 chopped yellow onion, rinsed under water to remove harsh bite
4 clove garlic, minced
1/2 tsp salt, or to taste
1/2 – 1 tsp sugar, to taste
1 Tbsp pepperoncini juice
3 Tbsp water, then more as desired
Move oven rack about 4-inch below broiler element, preheat broiler to high heat.
Place tomatillos and jalapeno on a baking sheet then place in oven and roast about 4 – 5 minutes until charred on top (keep a close on on things as they can char pretty quickly – especially the pepper).
Rotate veggies to opposite side and roast until charred on opposite side, about 3 – 5 minutes longer.
Slice pepper then add to a food processor along with onion, cilantro, garlic, salt, sugar, juice, water and tomatillos (and any juices on pan).
Pulse several times to a coarse puree.
Stir in more water to thin if desired.
Chill through in refrigerator in an airtight container.