Preheat the oven to 250 F.
In a dutch oven over medium heat, toast:
- 2 whole dried ancho chiles
- 2 whole dried pasilla peppers
- 2 teaspoons cumin seeds
- 1 teaspoon coriander seeds
Set aside, and allow to cool.
Deseed peppers, and cut them into strips. Grind deseeded peppers and toasted seeds into a powder, and set aside.
In the same dutch oven, render fat:
- Salt pork, cut into 1/4-inch cubes
Discard solids.
Season with salt and pepper, and brown on all sides:
- 2.5 pounds brisket flat, trimmed, cut into 2-inch cubes
Set beef aside.
Cook until softened (~10 minutes):
- 1 onion, chopped
- 3 Poblano peppers, minced
- 3 jalapeño peppers, thinly sliced
- 5 cloves garlic, minced
- Chili powder
Deglaze, and bring to a simmer:
- 4 cups chicken stock
- 1 Chipotle pepper in Adobo sauce, minced
- 1 tablespoon dried Mexican oregano
- 1 teaspoon masa harina
- 2 whole dried ancho or pasilla chiles (optional)
Cover with a lid slightly ajar, and place into the oven until meat is tender (~1.5-4 hours).
Season to taste with:
- Kosher salt
- Freshly ground black pepper
- Lime juice
Serve with:
- Lime wedges
- Fritos
- Sour cream
- Onion, chopped
- Cilantro, chopped