Cook penne pasta according to packet instructions. Drain and set aside.
Meanwhile,in a large frying pan heat the oil over medium heat, cook bacon until browned.
Stir in the garlic and cook for a few minutes, then add the mushrooms.
Cook,stirring constantly, for a couple of minutes until the mushrooms begin to soften.
Pour in the chicken stock, and bring to the boil. Allow to simmer over medium heat for about 3 minutes.
Add cooked penne to the pan, and stir until coated. Simmer uncovered until the sauce has reduced to just a few teaspoons in the bottom. Place generous servings onto plates and top with Parmesan cheese.