01 - Bring a large pot of salted water to a rolling boil. Cook the high-protein pasta according to package directions until al dente. Drain thoroughly and set aside.
02 - Heat a large nonstick skillet over medium-high heat. Add the ground beef and cook, breaking it apart with a wooden spoon, until browned and completely cooked through, approximately 6 to 7 minutes. Drain excess fat if needed.
03 - Add the chopped onion to the skillet and cook for 3 to 4 minutes until softened. Stir in the minced garlic and cook for an additional 1 minute until fragrant.
04 - Add the chopped spinach to the skillet and stir constantly until wilted, about 2 minutes.
05 - Reduce heat to low. Stir in the cream cheese and milk, mixing continuously until a smooth, creamy sauce forms. Add the Parmesan cheese, Italian herbs, black pepper, and salt. Simmer gently for 2 to 3 minutes.
06 - Add the cooked pasta to the sauce, tossing gently to coat every piece evenly. Taste and adjust seasoning as needed. Sprinkle with additional Parmesan and red chili flakes if desired. Serve immediately while hot.