
Prep the veggies: Remove the husks from the tomatillos and rinse them well. Cut the calabacita into large chunks (no need to peel it). Cut the stems off the jalapeños and serranos. Peel the garlic and chop the onion into large pieces.
Cook the tomatillos and calabacita: Add the tomatillos and calabacita to a medium saucepan and cover with water. Bring to a boil and cook for about 10 minutes, or until both are soft. Transfer the veggies to a plate or bowl and cool off. Reserve some cooking water for blending just in case is needed.
Sauté the aromatics:While the tomatillos and zucchini are cooking, heat the oil in a small skillet over medium heat. Add the onion, garlic, jalapeños, and serranos. Cook, stirring often, until everything softens and gets a little char—about 5 to 7 minutes. Let cool slightly.
Blend it all together: In a blender, add the cooked tomatillos, calabacita, sautéed onion, garlic, jalapeños, serranos, chicken bouillon powder, cilantro, and the oil from the pan. Blend until completely smooth. Note, if needed, add a few tablespoons of the cooking water to reach the consistency that you like.
Taste and add salt according to taste if needed.
Cool and store: Let the salsa cool to room temperature, then transfer to an airtight container. Refrigerate until ready to use. It makes 2 1/4 cups.