Preheat the oven to 425 degrees F.
Rinse the tomatillos and pierce with a fork. Put the tomatillos, garlic, Anaheim chiles, jalapenos, serrano chiles and onions on a sheet pan and drizzle with 2 tablespoons of the olive oil. Roast, turning occasionally, until dark brown in some areas but still retaining some integrity, 10 to 15 minutes. Roughly chop the tomatillos, Anaheim chiles and onions into 1/2-inch pieces; dice the garlic, jalapenos and serrano chiles.
Heat the remaining 2 tablespoons olive oil in large pot. Dredge the pork in the flour, and then brown in the pot over medium-high heat. Remove with a slotted spoon and set aside on a plate.
Reduce the heat to medium low; add the chicken stock and tequila, and bring to a simmer. Use a wooden spoon to dislodge any browned residue from the meat on the bottom of pan to create a rich broth. Add the meat and vegetables back to the pot. Add half of the cilantro, the oregano, cumin and bay leaves, and simmer, uncovered, until the pork falls apart easily when forked, about 3 hours. Add salt and pepper to taste.
Sprinkle with the remaining cilantro and serve.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.