Preheat the oven to 180C Fan.
Cut the chicken breasts into thin strips, pop them into a bowl and add the salt, pepper, garlic granules, and paprika. Stir to coat.
Melt the butter in a large pan with some cooking oil. Cook the chicken until it’s browned all over.
Remove it from the pan and set aside for now. Add the diced onion into the same pan and cook for about 5 minutes, until it softens.
Chuck in the garlic and cook for a further minute, before pouring in the chicken stock, and double cream
Get the chicken back into the pan and bring it to the boil. Simmer for a minute or so before adding in the grated parmesan and chopped parsley. Stir well.
Spoon some sauce into an oven proof dish. Mine was 20x30cm. Lay lasagne sheets over the top, then repeat for 3 layers. Use all the chicken up in the middle of the lasagne so that the final layer is just sauce.
Scatter the grated cheddar and parmesan over the top, then bake it for 25 minutes.
Leave to stand for a few minutes before cutting into portions, and enjoy.