Roast Capon With Rye Bread Stuffing

• 6 cubed day-old rye bread
• 1 cube chicken bouillon
• 1,600 gr capon
• 120 ml boiling water
• 60 gr onion (finely chopped)
• 60 ml boiling water
• 55 gr butter
• 50 gr celery (finely chopped)
• 7 gr parsley (finely chopped)
• 1 gr salt