Season both sides of the chicken with salt and pepper. Wrap a piece of bacon around each chicken breast. If the chicken is large, you will need two pieces of bacon (see note). Secure ends of bacon in place if desired with toothpicks sticking out of the sides of the chicken (so they are not in the way of cooking in the pan).
Heat 2 Tablespoons of the vegetable oil in a large, deep skillet over medium heat.
When the oil is hot, add the chicken. Do not move it as the bacon is cooking, it should release and not tear once cooked. If cooking too fast and starting to burn before the chicken is cooking, turn temperature down. If not browning fast enough, turn the heat up just a little. Cook until golden brown, approximately 5-7 minutes.
While the chicken is cooking, dice the rest of the bacon into a rough chop (approximately 4-6 slices).
Flip the chicken over and cook an additional 5 minutes until golden brown and also cooked all the way through. Add a little more oil if needed. If your chicken is browning too fast, reduce the heat to slow browning but continue cooking the chicken. The chicken is done when it is 165F in the thickest part. (If browned but not cooked through, place all the chicken in a baking dish and finish in the oven at 350F until the chicken reaches 165F internally and is cooked through).
Remove the chicken from the pan and set aside. Add the chopped bacon and cook until rendered, approximately 2-3 minutes.
Remove excess fat, leaving approximately 2 Tablespoons in the skillet. Leave the bacon in the skillet as well.
In a small bowl combine the cornstarch, garlic powder, and water. When the bacon is cooked, add the cornstarch to the bacon and stir.
Add the diced tomatoes, stock, and milk to the skillet. Bring to a simmer and cook until the sauce is thickened, approximately 5-8 minutes.
Remove the skillet from the heat. Add the parsley and Parmesan cheese and stir until melted. At this point, taste and season with additional salt, pepper, garlic, or Parmesan as desired. (The bacon and cheese makes this salty, so no need to season until now!). If the sauce is too thick or too strong/salty, add additional milk or stock until you reach your desired consistency and flavor.
Serve the chicken and sauce immediately over pasta, rice, potatoes, or vegetables.