Roast the poblano peppers, tomatoes, and garlic directly on a hot griddle until charred. Remove; peel the tomatoes and garlic, and place the peppers in a bag to steam for easier peeling.
2
Once the peppers have steamed, peel them, remove the seeds and veins, and cut into strips. Do the same with the jalapeños.
3
Heat a little oil in a casserole pot. Wash and halve the potatoes, add them to the pot with a pinch of salt, and sauté until lightly browned.
4
Slice the onion in half and then into strips; add it to the pot along with the roasted pepper strips and cook until softened.
5
Once the peppers and onions are tender, stir in the sliced red bell pepper briefly.
6
Add the shredded beef and mix well, pouring in a bit of the reserved beef broth to keep the mixture moist.
7
Blend the roasted tomatoes, garlic, oregano, cumin, black peppercorns, and a little water into a sauce.
8
Pour the blended sauce into the pot, season with a little salt, add a bit more broth, cover, and simmer for about 10 minutes to let the flavors meld.
9
While simmering, make sure the peppers are fully peeled, cleaned, and cut into thin strips, then add them to the pot and let everything boil until the sauce thickens slightly.
10
Before removing from heat, taste to ensure the beef is well seasoned and the sauce is rich, then serve.