1. Cook macaroni in boiling water with salt according to the package.
2. In a frying-pan, heat 1 tbsp olive oil (or vegetable oil) over medium heat, and cook chicken until no longer pink.
3. Add onion, shallot and mushrooms, cook until the onion is softer.
4. Add butter and melt it at medium heat, then add flour and mix well.
5. Add milk little by little, stir constantly. When the sauce gets thicker, season with ingredient A. Heat it in a low heat for a couple of minutes until the milk starts bubbling (do not overcook), mixing constantly.
6. Add macaroni and let it be well coated with the sauce.
7. Transfer into the baking dish.
8. Cover with mozzarella cheese, (or your choice of cheese) and bake in the oven at 200℃ for 30 to 40 mins.