Sauté Bacon: Sauté the bacon slowly in a pan until crispy, then remove and set aside.
Sauté Onion: In the same pan, add chopped onion and a little salt, and sauté until golden brown.
Prepare Chicken: Remove skin from chicken thighs, cut into bite-sized pieces, and season with salt and pepper.
Brown Chicken: Add chicken pieces to the pan and brown them for flavor.
Add Mushrooms and Garlic: Add sliced mushrooms and garlic to the pan, cooking until mushrooms release their moisture.
Deglaze with Wine: Pour in red wine and let it reduce, scraping up any browned bits from the bottom.
Add Stock and Simmer: Add chicken stock and bay leaf, cover, and simmer until chicken is tender.
Thicken Sauce: Mix cornstarch with water and add to the sauce to thicken.
Combine with Pasta: Toss the cooked penne pasta with the chicken and sauce.
Finish and Serve: Stir in cognac (if using), garnish with parsley and parmesan, and serve hot.