Put a rack 4 inches below the broiler and preheat it.

Put the tomatillos and jalapeno peppers on a baking sheet and broil for 5 minutes or until blackened in spots.

Flip them over with tongs and cook for a further 5 minutes until blistered.

Put the onion, cilantro, 2 tablespoons of the lime juice and ½ teaspoon salt in a blender or food processor.

Add the tomatillos and jalapenos (with their skins and juices) and pulse until mostly smooth.

Add more salt and/or lime juice if needed.

If you want a creamy salsa, let it cool down in the blender or food processor and add 1 or 2 avocados and blend again.