Boil pasta with salt n oil little but don't over cook it will be cooked in oven also.

In a pan add butter than chicken and cook till colour changes add white pepper, black pepper powder, salt, garlic poedertcook till done

Make cheese sauce :
Add butter 4tbsp melt it n add maida stir and fry till aroma comes add milk n cook keep stirring, add salt, n cheese cook till thick sauce is made, add chicken in it and cook for few mins. Add oregano n mix.

Oven should be preheatd
Grease a glass dish. In a bowl mix macaroni and cheese sauce and pour this in oven dish, top with cheese, crushed red chillies (optional) some oregano and bake it