Chicken Tetrazini

• 1 chicken
• 700 ml chicken stock
• 160 gr mushrooms (fresh sliced)
• 160 ml cream (light)
• 75 gr butter
• 65 gr flour
• 50 gr celery (chopped)
• 45 gr thi spaghetti
• 45 gr butter
• 40 gr parmesan cheese (grated)