Preheat grill to high.

Grill tomatillos until lightly browned and soft, about 6-8 minutes, turning occasionally.

Transfer grilled tomatillos to a plate to cool.

Alternatively, bring 2 cups of water to a boil in a saucepan.

Add tomatillos to boiling water and simmer, covered, until soft, about 4 minutes.

Stir occasionally to ensure even cooking.

Drain tomatillos, reserving cooking liquid.

Transfer tomatillos to a food processor.

Process to a coarse puree.

Add jalapenos, cilantro, onion, garlic, lime juice, sugar, salt, and pepper to the food processor.

Process just to mix.

If the mixture is too thick, add a few tablespoons of water or tomatillo cooking liquid to thin.

Add avocado to the food processor.

Process briefly to just mix, ensuring the avocado remains in small pieces.

Adjust seasoning with salt or lime juice to taste.

Serve fresh, ideally within 1-2 hours.