To make the chicken base, pressure cook the chicken peieces with salt and pepper for one whistle. Allow it to go on its own. Reserve all the stock.
Cook the spaghetti as per pack instructions till el dente and drain.
In a saucepan, heat the oil and butter. Fry the garlic and then saute the onions just till wilted.
Fry the flour and then pour the milk, cream and the reserved stock and whisk till the mixture is smooth.
Add the chicken, spinach and white pepper powder and allow it to just bubble. Adjust seasoning.
Preheat oven to 180 degrees. Keep a 13x9 inch glass pan ready for baking.
Spread the chicken mixture at the bottom. Top with the spaghetti. Sprinkle the mozarella cheese on top. Sprinkle the red chilli flakes and italian seasoning.
Bake for 20 minutes till the cheese is melted.
Enjoy hot with a salad on the side.