In a Dutch oven, add meat with water and salt. Cook at medium-low until the meat is tender, about 2 hours (In a pressure cooker, this takes about 30 minutes). Transfer meat to a plate and shred with two forks.
In a large bowl, add shredded meat, dry cooking wine, olive oil, lime juice, garlic powder, cumin, onion powder, salt, and pepper. Let the meat marinate at room temperature for 20 minutes.
Meanwhile, make the mac and cheese. In a saucepan, cook macaroni according to package instructions until al dente. Drain and set aside.
In a large pot, melt butter over medium-high heat. Whisk in flour to create a roux. Whisk in milk and Knorr Chicken Bouillon then cook for 1 minute until the mixture thickens slightly.
Reduce heat to medium-low. Add the cheddar and stir until cheese is completely melted. Add in cooked pasta and carefully stir to combine.
To finish the vaca frita. In a skillet, heat 1 tablespoon olive oil over medium-high. Sauté onions until tender then add the marinated shredded beef. You may have to do this in batches as to not crowd the pan. Pan fry for about 10 minutes, until the beef gets crispy. Transfer to a plate.
Serve mac and cheese topped with vaca frita. Garnish with green onions. Enjoy!