Chicken:
Tuscan sauce:
Preheat the oven to 180°C (160°C fan-forced).
Bring 3 litres of water to the boil with the salt. Cook the pasta on par-boil, then drain and let cool.
Lay the bacon in an unheated, large pot (no oil) over medium-high heat. Cook for 3 minutes until golden, then turn and cook for another 2 minutes. Discard the bacon on a paper towel-lined plate then chop into 1 cm pieces. Discard the bacon fat.
Cook chicken - Sprinkle salt and pepper over the chicken. In the same pot on medium-high heat, melt the butter. Cook the chicken for 4 minutes on each side, then transfer to a plate. Rest for 5 minutes, then slice into 1 cm thick slices.
Tuscan sauce - Melt the butter in the same pot still on medium-high heat. Add the garlic and cook for 30 seconds. Add the wine, stir, then simmer rapidly for 2 minutes or until mostly evaporated. Lower the heat to medium, add the flour and stir for 1 minute. Slowly pour in the milk - the mixture will thicken. Once the flour and milk are combined, add the cream and chicken stock. Whisk until lump-free. Bring to a simmer and stir regularly with a wooden spoon for 4-5 minutes until the sauce is thick enough to coat the back of the wooden spoon. Stir in the onion and garlic powder, salt, pepper and two-thirds of both the bacon, parmesan, and mozzarella. Once the cheese melts, the sauce should be thick and creamy.
Assemble and bake - Stir in the spinach, chicken, sun-dried tomatoes, most of th bacon (reserve some for topping) and pasta. Pour into a 30 x 22 cm baking dish, sprinkle with remaining parmesan, followed by the mozzarella and bacon. Bake for 20 minutes until the cheese is melted and golden.
Serve - Stand for 5 minutes before serving. Garnish with parsley, if desired.