Preheat the oven to 450 degrees and line a baking sheet with parchment paper. Add the tomatillos (cut-side down), onion and garlic to the baking sheet. Drizzle with olive oil and toss to coat. Bake for 15 minutes.
Remove from the oven and allow to cool for 10 minutes. Add everything from the baking sheet to a food processor** (being sure to remove the garlic skins) with the rest of the salsa ingredients. Pulse until combined. Taste and adjust seasonings as needed.
Allow to cool before placing in the fridge. This will last for 3-5 days in the fridge.
*When you remove the husks, the tomatillos will have a slightly sticky layer on the outside. Be sure to rinse them under warm water before cutting in half.
**Be sure to squeeze all of the juices and oil off of the parchment paper into the food processor.
Calories: 226kcal, Carbohydrates: 21g, Protein: 3g, Fat: 16g, Saturated Fat: 2g, Polyunsaturated Fat: 2g, Monounsaturated Fat: 11g, Sodium: 588mg, Potassium: 688mg, Fiber: 6g, Sugar: 11g, Iron: 2mg