01 - Bring a large pot of salted water to a boil. Cook pasta until al dente according to package directions. Reserve 1/2 cup of pasta water before draining.
02 - Melt butter with olive oil in a large skillet over medium heat. Add minced garlic and cook 1–2 minutes until fragrant and pale golden, taking care not to brown.
03 - Reduce heat to medium-low. Pour in heavy cream and whole milk, stirring constantly. Simmer gently for 2–3 minutes until slightly thickened.
04 - Stir in grated Parmesan, salt, black pepper, and red pepper flakes. Continue stirring until cheese completely melts and sauce becomes smooth and velvety.
05 - Add drained pasta to the skillet and toss thoroughly to coat. If sauce appears too thick, incorporate reserved pasta water gradually until reaching desired consistency.
06 - Remove from heat. Gently fold in chopped parsley, basil, chives, and lemon zest. Taste and adjust seasoning as necessary.
07 - Plate immediately, garnishing with additional herbs and Parmesan if desired. Serve while hot for best texture and flavor.