Creamy Cheesy Garlic Butter Linguine with Ground Beef (30 Minutes)

Ingredients

• 12 oz (340 g) linguine
• 1 tablespoon kosher salt, for the pasta water
• 1/2 cup (120 ml) reserved pasta water
• 1 lb (450 g) ground beef, preferably 85/15
• 1 small yellow onion, finely chopped
• 4 tablespoons (56 g) unsalted butter
• 5 cloves garlic, minced
• 1 teaspoon Italian seasoning
• 1/2 teaspoon red pepper flakes, optional
• 1 teaspoon kosher salt, plus more to taste
• 1/2 teaspoon black pepper
• 1 cup (240 ml) heavy cream
• 1/2 cup (120 ml) beef broth
• 1 cup (115 g) shredded low-moisture mozzarella
• 1/2 cup (50 g) freshly grated Parmesan, plus more for serving
• 2 tablespoons chopped fresh parsley