Preheat oven to 375°F (190°C).

Line a baking sheet with foil and spray with cooking spray.

Place tomatillos, onion, and jalapeno on the prepared baking sheet.

Roast in the preheated oven for 30 minutes, flipping the tomatillos after 15 minutes.

Let the roasted vegetables cool for about 10 minutes after removing from the oven.

Transfer the roasted vegetables to a food processor.

Add cilantro, lime juice, and salt to the food processor.

Pulse to incorporate all ingredients until desired consistency is reached.

Add a pinch of sugar to cut through the acidity and heat, if desired.

Refrigerate for at least one hour to allow flavors to meld.

Taste and add extra salt if needed after chilling.

Serve with tacos, chips, enchiladas, or other dishes.