Gather all the ingredients. Cook the tomatillos, onion, and the cleaned and seeded pasilla chiles. Once cooked, transfer everything to a blender and blend together with a pinch of salt and the chicken bouillon cube. Set the sauce aside.

In a pot, heat the oil and brown the chicken pieces on both sides until golden yellow.

Gradually pour in the sauce along with the vinegar and bring to a boil. Turn off the heat. Done!