Cook the linguine according to package instructions until al dente. Drain and set aside.
In a large skillet over medium heat, cook the ground beef until browned and cooked through. Drain excess fat.
Add the minced garlic to the skillet with the beef and sauté for about 1 minute until fragrant.
Reduce the heat to low and stir in the butter until melted.
Pour in the heavy cream and bring to a gentle simmer. Cook for 2-3 minutes, allowing the sauce to thicken slightly.
Stir in the mozzarella and Parmesan cheeses, and continue to cook until the cheese is melted and the sauce is smooth.
Season with salt and pepper to taste.
Add the cooked linguine to the skillet and toss to coat the pasta evenly with the sauce.
Sprinkle with fresh parsley before serving.