Turn the oven on to Hi Broil
Remove Husks from the Tomattillos, wash and slice each one in half
Slice the onion into quarters
Add the sliced tomatillos, onions, garlic (unpeeled) and jalapeno to a large bowl.
Drizzle the olive oil over the veggies in the bowl and mix to coat.
Place the vegetables from the bowl onto a baking sheet with the tomatillos cut side down.
Place the baking sheet into the oven and broil for 7-10 minutes or until brown.
Remove the baking sheet from the oven. Peel the garlic and remove the stem and seeds from the jalapeno.
Place all roasted vegetables, plus the lime juice and cilantro into a food processor and pulse until slightly chunky.
Refrigerate for 2 hours to combine flavors, serve.