Place the chilacas, garlic and onion on a baking sheet.

Place under broiler, until charred. 5 to 7 minutes.

Be sure to watch the garlic, it will char quickly.

Remove from broiler cover with dish towel and allow to steam for about 5 minutes.

Remove charred skin, stem and seeds.

Remove skin from garlic and onion.

Place chilacas, garlic, onion and oregano into a molcajete or blender along with a splash of water.

Puree until smooth.

Season to taste with salt and pepper.