Cook the tomatillos and guajillo chili pepper. You can also add a few arbol or serrano peppers if you like it spicier. Cut the beef steak into strips. Heat oil in a pan, add the beef, season with salt and pepper, and cook until it releases its juices. Meanwhile, peel and cut the potatoes.

Once the beef has cooked off its juices, add the potatoes and let them brown a bit. When the tomatillos are cooked, blend them with their cooking water, onion, garlic, and a pinch of cumin until very smooth. Strain the sauce and pour it over the meat.

If needed, add a little water, then add the cilantro sprigs, salt, and pepper. Cover and simmer on low heat until the meat and potatoes are tender. Once done, remove the cilantro sprigs and serve. Enjoy!