Ingredients
1 pound tomatillos, husks removed, rinsed
1 garlic clove
2 jalapeño or serrano chiles, or to taste
1/3 cup coarsely chopped white onion
1 cup cilantro leaves and top part of stems
1 teaspoon kosher or coarse sea salt, or to taste
3 teaspoons vegetable oil
Directions
Place the tomatillos, garlic, and chiles in a medium saucepan and cover with water. Bring to a simmer and cook until the tomatillos change from bright green to pale green and are soft but not falling apart, about 10 minutes. With a slotted spoon, transfer the tomatillos, garlic, and one of the chiles to a blender or food processor. Add the onion, cilantro, and salt and purée until smooth. Taste for heat, and add more chile if necessary until you have the desired amount of heat. Heat the oil in a medium saucepan over medium heat until hot but not smoking. Pour the salsa into the saucepan and cook, stirring occasionally, until thickened slightly, 6 to 8 minutes. Serve hot or warm.
Source: "Food52" https://food52.com/recipes/22530-cooked-green-salsa-salsa-verde