Turn your Instant Pot to the sauté setting and add the lean ground beef. Cook it until nicely browned, breaking it up with your spoon as it cooks. Once browned, drain any excess fat if needed.
Sprinkle the taco seasoning and all-purpose flour over the cooked beef. Stir well to coat the meat evenly and let it cook for about a minute to toast the seasoning and flour slightly.
Add the entire can of Rotel diced tomatoes with green chilies, the beef broth, and the penne pasta. Stir everything together, making sure the pasta is submerged in the liquid to prevent burning.
Seal the Instant Pot lid and set the valve to sealing. Cook on high pressure for 5 minutes. Once the cooking time is up, perform a quick release carefully to release the steam.
Open the lid and stir in the jar of salsa con queso and half of the shredded Mexican cheese blend. The residual heat will melt the cheese into a luscious, creamy sauce.
Taste and season with salt and pepper as needed. Sprinkle the remaining cheese on top, garnish with fresh cilantro or sliced green onions if you like, and serve hot. Enjoy your comforting, cheesy taco pasta!
