Ask your butcher (or do it yourself) to cut the pork into small pieces, about 1 1/4 inches (3 cm) per side.

Heat a wide, shallow pot or pan and add the oil.

Add the pork, a little salt, and the water. Let the pork release its juices, then stir occasionally. Continue cooking until the water has evaporated and the pork starts to brown. This will take a while. Set aside.

Once the pork is browned, in a small saucepan add half a cup of water, the cleaned chiles (no need to remove the seeds), 1/4 of the onion, half of the chopped garlic, the chicken bouillon, and a little pepper. Bring to a boil, then turn off the heat and cover. Let sit for 20 minutes so the chiles soften.

In another pan, heat a little oil over high heat and add about one onion's worth, the rest of the garlic, and sauté until translucent.

Add the mushrooms and a little salt. Cook until the mushrooms reduce to half their volume. Remove from heat, place in a colander to drain, and set aside.

Cut sheets of aluminum foil about 12 x 12 inches (30 x 30 cm). Use 3 sheets for each mixiote.

Blend the chiles with their cooking liquid VERY CAREFULLY (remove the blender lid's center cap and cover with a kitchen towel or paper towels, as blending hot liquids creates pressure) until smooth.

Slowly pour the blended mixture through a fine mesh strainer to get a thick, smooth sauce. Set aside.

Take a stack of 3 foil sheets, shiny side up, and place 5 tablespoons of pork (about 7 oz or 200 grams) in the center.

Add 3 tablespoons of mushrooms.

Add 3 or more tablespoons of sauce and some strips of the remaining onion.

Carefully fold the corners of the foil square in first, then the rest, to form a tight packet. Do the same with the other 2 sheets in the stack. Make sure nothing leaks. Seal tightly, but don't tear the foil.

Repeat until all the packets are made.

In a steamer or deep pot with a rack or steaming basket, bring 2 cups (1/2 liter) of salted water to a boil.

Once boiling, carefully place the packets seam side up.

Cover and steam for 30 minutes.

Remove, place each packet in a deep bowl, and open carefully as they will be very hot and full of steam.

Enjoy with beer, tortillas, or rice.