Bring a large pot of salted water to a boil. Cook pasta according to package instructions until al dente, about 8-10 minutes. Drain and set aside.

In a large skillet, heat olive oil and butter over medium-high heat. Add diced onion and sauté for 3-4 minutes until translucent.

Stir in minced garlic and red chili flakes, cooking for an additional minute until fragrant.

Add chicken pieces, seasoning with salt, pepper, and Italian seasoning. Cook for about 5-7 minutes until golden brown and cooked through.

Pour in tomato sauce and half and half, stirring to combine. Simmer for 3-5 minutes until sauce thickens.

Toss in cooked pasta, ensuring every strand is coated. Stir gently for 1-2 minutes.

Plate the pasta, sprinkle with Parmesan cheese and parsley, and serve hot.