Bring a large pot of lightly salted water to a boil. Add the penne pasta and 1 tablespoon of olive oil to the pot, and cook until pasta is almost tender, about 6 minutes. Drain.
In a large skillet 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 a boil. Allow to simmer over medium heat for about 3 minutes. Add cooked pasta 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.
