01 - Cook fettuccine or linguine in a large pot of salted boiling water according to the package instructions until al dente. Reserve 1/2 cup pasta water, then drain.
02 - In a large skillet over medium heat, melt unsalted butter with oil from sun-dried tomatoes. Add minced garlic and cook for 1 minute, stirring until fragrant.
03 - Stir in chopped sun-dried tomatoes and optional crushed red pepper flakes. Cook, stirring, for 2 minutes.
04 - Pour heavy cream and whole milk into the pan, stirring to blend. Bring to a gentle simmer, then incorporate grated Parmesan, salt, and black pepper. Mix continuously until cheese has melted and the sauce has thickened, approximately 3 to 4 minutes.
05 - Transfer drained pasta into the skillet. Toss well to ensure thorough coating in the Alfredo sauce. If the mixture is too thick, gradually add reserved pasta water for desired consistency.
06 - Remove from heat. Fold in chopped fresh basil and check seasoning, adjusting if necessary. Plate immediately, garnishing with extra grated Parmesan.