Season beef with salt and pepper to taste. Place an uncovered instant pot or oven-proof Dutch oven over medium-high heat, and add olive oil.

When oil is hot, add beef. Stir until beef is well browned on all sides, about 5 minutes.

Add dark beer and continue to simmer until liquid has reduced by half, about 15 minutes. Add Molli Mexico City cooking sauce and cilantro springs, and if using instant pot, 1/2 cup water. Secure lid and set to "pressure cook" for 45 minutes. to bring contents of pot to a simmer. Reduce heat to low, and simmer for 45 minutes.

If using Dutch oven, simmer, covered on the stove over low heat, for 3 to 3 1/2 hours.

When meat is fully cooked, place a large pot of lightly salted water over high heat to bring to a boil.

After pressure has dropped in instant pot, follow manufacturer's instructions to remove lid. Using two forks, finely shred meat. Discard cilantro stems. Loosely cover pan and return it to low heat to keep warm.

Add penne to boiling water. As it cooks, scoop out 1/2 cup water and reserve. Cook pasta to taste, then drain well. Return pasta to pot, and add butter and 1/4 cup queso cotija or feta; mix gently until butter has melted. If needed, add a little reserved cooking water to loosen.

To serve, lift pasta into each of six shallow bowls. Spoon beef ragù over top. Sprinkle each bowl with a pinch of cilantro, and a spoonful of cheese. Provecho!