2 small yellow onions, cut into 1-inch wedges
4 cloves garlic, peeled
1 jalapeño pepper, left whole (or remove the ribs and seeds for a mild salsa)
3 tablespoons extra virgin olive oil
1 teaspoon salt
1 teaspoon ground cumin
1/8 teaspoon sugar
3/4 cup packed fresh cilantro leaves, plus a bit more for serving
Set an oven rack about 5 inches beneath the heating element and preheat the broiler. Line a rimmed baking sheet with heavy-duty aluminum foil. Place the tomatillos, onions, garlic, jalapeño pepper and oil directly on the prepared baking sheet and toss with your hands or a rubber spatula. Broil until softened and slightly charred, 10-12 minutes. Transfer the vegetables and juices to a food processor fitted with the metal blade. Add the salt, cumin, sugar, and cilantro and pulse until chunky. Taste and adjust seasoning, if necessary. Transfer to a bowl and sprinkle with chopped cilantro if desired. Serve the salsa warm, at room temperature, or slightly chilled. Make-Ahead: The salsa can be made up to 3 days ahead of time and stored in a covered container in the refrigerator.