Begin by bringing a large pot of salted water to a rolling boil. Add the linguine pasta, cooking it according to the package instructions until it’s al dente, about 9–11 minutes. Once cooked, drain the pasta in a colander, reserving ½ cup of the pasta water. Set both aside.

In a large skillet, melt 3 tablespoons of unsalted butter over medium heat. Add the minced garlic and finely diced onion. Sauté for about 2-3 minutes until the onion is translucent and tender.

Add the ground beef to the skillet, breaking it apart. Season with salt, black pepper, and Italian seasoning. Cook for about 6-8 minutes until browned, stirring occasionally. Drain excess fat from the skillet.

Lower the heat slightly and add 1 cup of heavy cream, stirring to combine. Bring to a gentle simmer, allowing it to thicken for about 4-5 minutes. Add the freshly grated Parmesan cheese and optional red pepper flakes, stirring until the cheese melts.

Gently toss the cooked linguine into the skillet with the creamy beef mixture. Use tongs to coat the pasta evenly with the sauce, adding reserved pasta water gradually to achieve desired consistency.

Sprinkle with freshly chopped parsley or thyme. Serve hot, topped with extra parmesan cheese and black pepper if desired.