Add the tomatillos to a baking sheet along with the jalapenos and onion wedges. Toss with 1 tablespoon of the olive oil and roast about 7 minutes. Turn the vegetables, add the garlic and roast until everything is slightly softened and charred, another 7 to 8 minutes. Set aside to cool.
Peel the garlic and remove the stems and seeds from the jalapenos. Add the roasted vegetables to the bowl of a food processor and pulse until still slightly chunky but well combined. Add the cilantro, lime juice and 1 teaspoon salt and pulse until incorporated. With the processor running, stream in the remaining 3 tablespoons olive oil until the salsa is slightly runny but not smooth. At this point you can season with additional salt if desired.
Serve with chips or as a salsa for tacos and burritos.