Pug's Serrano Pepper Base

Wash and de-stem the serrano peppers. Lay the serranos on a sheet of aluminum foil so that they don't touch. Broil in an oven, turning once, until roasted browns and blacks appear on both sides. Remove and let cool. Meanwhile, heat the olive oil in a medium skillet over medium heat. Coarsely dice the onion and add to the oil. As the onion starts to lose its moisture to the pan, sprinkle the sugar over the onions as evenly as possible and let sit a minute before stirring. Then stir constantly for 5-8 minutes until the onions take on a deep brown coloration and remove from heat. Transfer the serranos and the onions into a food processor (8 cups seems about right). Puree until smooth, scraping sides as needed. This makes an enormous amount of pepper base, given that I tend to put 2 teaspoons at a time in sauces and chilis, so I freeze the results in ice cube trays. I clean trays, spray with nonstick spray (olive oil), and then put 2 teaspoons into each ice cube spot and freeze. When frozen, I pop the cubes out into freezer bags and just wash the trays.