Heat the oven to 180°C (360°F) or 160°C (with fan option on) or gas mark 4.
Place a large pan of water over high heat and bring to a boil. Lightly season with sea salt, then add the pasta and cook for about 7-9 minutes.
Look at the instructions on your pasta packaging. See how long it tells you to boil the penne for, and drain the pasta 3-4 minutes before this time.
Whilst the pasta cooks, heat a skillet to medium heat, add the olive oil and the chicken and stir-fry for about 5 minutes, until the chicken is lightly browned on all sides.
Heat a small skillet over medium heat, add the bacon and cook until crispy, for about 4-5 minutes, then transfer on a plate covered with kitchen paper to absorb the grease in excess.
Drain the pasta al dente, and transfer the pasta back into the pan. Add in the tomato sauce, chicken and bacon and mix all the ingredients. Season with sea salt and black pepper to taste.
Transfer the ingredients in a 6x8 inches baking dish or an oven-friendly pan, and sprinkle the Parmesan cheese and mozzarella all over the top.
Bake the chicken and bacon pasta for around 15-20 minutes, or until the cheese on top is golden brown. If you want some nice crunchy brown spots, set the baking dish under the grill for 2-3 minutes extra. Remove from the oven, allow to cool slightly, sprinkle with chopped parsley and serve.