Corned Beef Smash

• 1 box instant mashed potatoes
• 1 stick margarine
• 1 pot with lid
• 1 plastic zip lok bag to mix
• 1 water
• 1 stiring spoon
• 240 ml milk (dried power)
• 120 gr cheese (grated)
• 2 packages onion soup mix
• 1 package corned beef