The nontraditional step of cooking the onion and chiles gives them a full, roasted flavor that goes beautifully with the mellow avocado. Just don’t stand too close to the pan while cooking the chiles, or the fumes will burn your nose.
2 teaspoons unsalted butter
2 teaspoons vegetable oil
3 serrano chiles, stemmed and cut in half lengthwise (remove seeds for a milder guacamole)
1 onion, diced
11/2 tablespoons fresh lemon juice
salt to taste
3 ripe avocados, halved, peeled, and pitted
1/2 cup chopped fresh cilantro (optional)
In a medium skillet melt the butter with the vegetable oil over high heat. Add the serrano chiles and onion and sauté for 3 to 5 minutes or until lightly browned. Add the lemon juice and salt and remove from heat.
Carefully transfer the chile halves to a cutting board and finely chop. Then put the serranos and onion in a mixing bowl (or a molcajete, if you have one), add the avocado and cilantro, and thoroughly mash. Season with salt and serve immediately. Makes 2 to 21/2 cups.