For National Burger Day Tien Windaur whips up one of his "Flathead Monsters" on Wednesday, May 28, at Tien's Place in Columbia Falls. The burger is not officially on the menu but Tien has been making it as a sort of private challenge for customers for 11 years. If someone can eat the whole thing, it's free. The "Flathead Monster" contains three patties, nine slices of cheese, sauteed mushrooms, lettuce, onion, tomato, and two grilled cheese sandwiches for the bun all held together with two chop sticks and served over french fries. According to Tien, in 11 years only four customers have been able to eat the whole thing. For something a little more manageable Windaur offers the "Chad" a burger named after the customer who initially request that Tien create the perfect burger. The "Chad" has two patties, cheese, mushrooms, lettuce, tomato and onion with bun for $8.95. (Brenda Ahearn/Daily Inter Lake)