preheat oven to 400°.

prepare linguine according to the instructions on the box.

in a large skillet over medium heat, melt 1 tablespoon butter.

cook garlic until fragrant, 1 minute, then add in mushrooms and cook until most of their moisture is released and they are golden on both sides.

add chicken and cook until partially cooked, 5 minutes.

transfer mushrooms and chicken to a plate and set aside.

return skillet to medium heat and melt remaining 2 tablespoons butter.

whisk in flour until completely combined, then slowly whisk in chicken stock and bring to a simmer.

pour in cream and again bring to simmer over low heat, stirring occasionally and allowing the sauce to thicken, about 10 minutes.

place pasta into a baking dish along with chicken and mushrooms.

pour sauce over mixture and season with salt and pepper.

toss to combine.

sprinkle with parmesan and bake for 20 minutes, until sauce is bubbling and parmesan crust is golden.

sprinkle with parsley and serve.