Bring a large pot of generously salted water to a boil. Cook the fettuccine pasta according to package directions until al dente. Reserve 1/2 cup of the pasta water, then drain the pasta.

While the pasta is boiling, heat the olive oil and butter in a large skillet over medium-high heat. Season the chicken pieces with salt and black pepper, add to the skillet, and cook for 5-7 minutes until lightly browned and cooked through.

Reduce the skillet heat to medium. Add the minced garlic and sauté for 1 minute until fragrant.

Lower the heat to medium-low. Add the Boursin cheese and heavy cream to the skillet. Stir continuously until the cheese melts into a smooth sauce.

Add the drained fettuccine to the skillet. Gradually pour in the reserved pasta water while tossing everything together, continuing until the sauce smoothly coats the pasta.

Garnish with red chili flakes and fresh chopped parsley. Serve immediately.