Season chicken with salt & pepper
Heat oil in skillet, sear chicken 4–5 min each side
Remove chicken, set aside
Add butter, sauté onion until translucent
Add mushrooms, cook until golden
Stir in garlic & thyme briefly
Deglaze with marsala wine, reduce by half
Stir in broth & cream, simmer
Return chicken, simmer 2–3 min
Cook pasta al dente, drain
Toss pasta with sauce & cheese
Garnish with parsley & serve