Boil water in a large saucepan and cook spaghetti. Dice the chicken fillet and put it in a hot skillet. Fry the chicken until white. Pour in warmed milk and boil.
Add cheese, garlic and salt to boiling milk to taste. Boil the sauce until it thickens, then remove from heat and add to spaghetti. Immediately serve spaghetti with chicken in milk and cheese sauce on the table, sprinkled with grated cheese, herbs and black pepper.