Preheat your oven to 425°F (220°C) to roast the tomatillos, onion, and garlic.

Place the halved or quartered tomatillos, onion pieces, and unpeeled garlic in a baking dish.

Roast the vegetables for about 15 to 20 minutes until tender and skins begin to char.

Let roasted vegetables cool for a few minutes, then peel the roasted garlic cloves.

In a blender, combine the roasted tomatillos, onion, peeled garlic, cilantro, lime juice, and jalapeños.

Taste and adjust salt; if desired, add olive oil and blend again until silky.

Transfer salsa to a bowl and chill in the refrigerator for at least an hour before serving.