Heat the olive oil and butter in a large skillet with deep sides over medium high heat. While it heats up whisk the flour, garlic powder, dried thyme, salt and pepper together in a bowl. Toss the chicken breasts in the flour mixture to coat them, then get three of them into the hot pan. Let them brown for just 2 minutes on each side, then remove them to a plate and repeat with the other 3 chicken breasts. Once all of the chicken is cooked and removed from the pan, add in the mushrooms, garlic and onion and let them soften for a couple of minutes.

Pour in the marsala wine, chicken stock and Worcestershire sauce and give it all a stir. Let the sauce come to a gentle boil and cook for 2-3 minutes to let it slightly reduce and thicken. Then add the chicken back in, season it all with an extra pinch of salt and pepper, and let it cook together for 15 minutes. While the chicken and sauce cook, get a large pot of water on the stove and bring it to a boil. Cook the linguine just until it is tender for 8-10 minutes, then drain it and toss it into the pot of chicken and sauce. Transfer the pasta and chicken to a platter and serve immediately family style!