Salmon Cakes With Lemon

• 2 green onions (chopped)
• 1 egg
• 1/4 stick
• 300 gr crumbled salmon fillets (cooked)
• 240 ml mayonnaise
• 75 gr cornflake crumbs
• 28 gr butter
• 26 gr celery (finely chopped)
• 16 ml lemon juice
• 16 gr horseradish prepared