Bring a large pot of salted water to a rolling boil. Once boiling, add the linguine and cook according to package instructions until al dente, usually about 8-10 minutes. When ready, drain the pasta and reserve 1/2 cup of the pasta water.

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

Add the ground beef to the skillet, seasoning the meat with salt, pepper, and Italian seasoning. Cook for approximately 6-8 minutes, stirring occasionally until beef is browned and no longer pink.

Lower the heat slightly and pour in 1 cup of heavy cream, stirring gently to combine. Bring to a gentle simmer for about 4-5 minutes. Stir in the freshly grated Parmesan cheese and red pepper flakes until the cheese is melted.

Add the cooked linguine directly into the creamy beef sauce, tossing gently to coat all the noodles. If the sauce appears too thick, use the reserved pasta water to reach desired consistency.

Remove the skillet from heat. Garnish with chopped fresh parsley or thyme and serve immediately, adding extra Parmesan and freshly cracked black pepper on top if desired.