Cook the Chicken:

Cook fettuccine according to package instructions. Drain and set aside.
Cook the Chicken:

Heat olive oil in a large skillet over medium-high heat. Season chicken pieces with salt and pepper.
Cook chicken until browned and cooked through, about 5-7 minutes. Remove from skillet and set aside.
Cook the Mushrooms:

In the same skillet, add a bit more olive oil if needed. Sauté mushrooms until tender and golden, about 5 minutes.
Add garlic and cook for another minute until fragrant.
Make the Alfredo Sauce:

Reduce heat to medium. Add heavy cream and chicken broth to the skillet, stirring to combine.
Bring to a simmer, then stir in Parmesan cheese and dried thyme. Cook until sauce is thickened, about 3-5 minutes.
Combine:

Return the cooked chicken to the skillet and toss to coat in the sauce.
Add the cooked fettuccine and gently toss to combine everything.
Serve:

Garnish with chopped parsley and serve immediately.
Deliciously creamy and comforting!