Remove husks from the tomatillos and rinse with cold water.
Heat a comal or a cast iron pan, lined with foil, over medium-high heat. Add tomatoes, peppers and garlic clove. Roast, turning a few times ensure even browning. Remove the peppers when they have toasted but not burned. Let the tomatoes and the garlic burn slightly. Remove from the pan.
Peel the garlic and place in a molcajete. Add the salt and grind to a consistency of a paste.
Add the chilies to the molcajete and grinds to a paste.
Add the roasted tomatoes and grind gently to leave some chunks behind.