Fry the onion in oil over a medium heat for about 3-4 minutes. Add the mushrooms and garlic powder and cook for 3 minutes. Add the spinach and cook for a further 2 minutes to reduce down. Remove from heat and place to one side.
Place in a bowl the cream cheese, parmesan and mix. Once cooled down add the onions, mushrooms and spinach mix.
Spoon the mix into the chicken breasts, wrap the filled chicken breasts with streaky bacon. Place on a non-stick roasting tin and cook for 40-45 minutes at 180C until the chicken is thoroughly cooked.