Step 1: Season the chicken breasts with salt and pepper. In a large skillet, heat the olive oil over medium heat. Cook the chicken for about 6-7 minutes on each side until cooked through. Remove and shred.
Step 2: In a large pot, bring salted water to a boil. Add linguine pasta and cook until al dente. Drain and set aside.
Step 3: In the same skillet, melt 4 tablespoons of butter over medium heat. Add onion and mushrooms, sauté for 5-7 minutes. Stir in garlic and cook for an additional minute.
Step 4: Sprinkle flour over the mixture, stir, and cook for a minute. Gradually add chicken stock, stirring until thickened. Slowly add half and half, simmer until creamy.
Step 5: Add shredded chicken and cooked linguine to the sauce, toss to coat. Stir in 1 cup of mozzarella cheese.
Step 6: Preheat oven to 350°F (175°C). Transfer mixture to a greased baking dish. Top with remaining mozzarella and Parmesan cheese, dot with remaining butter.
Step 7: Bake for 20-25 minutes until cheese is bubbly and golden. Let cool for a few minutes before serving.
Notes
For extra flavor, add herbs like thyme or parsley. You can substitute linguine with any pasta shape you prefer.