Hamburger with Double Cheddar Cheese, Grilled Vidalia Onion and Horseradish Mustard Sauce

I just made the most insane tasting hamburgers tonight. The spicy horseradish mustard sauce and grill onion and sliced cheese gave these hamburgers flavor beyond words. Instead of cheddar cheese I used white seriously sharp cheese and yellow extra sharp then added a tablespoon of water to the hamburger mixture so they would be mouth watering moist. I think you will enjoy these hamburgers as much as we did.
I lost the picture I took of them tonight in the download process. But that is ok, that just gives me a excuse to make them again real soon.

Ingredients:

2 pounds freshly ground chuck

Salt and freshly ground black pepper

8 slices white cheddar cheese, sliced ¼ inch thick

8 slices yellow cheddar cheese, sliced ¼ inch thick

8 hamburger buns

Horseradish Mustard, recipe follows

8 leaves Romaine Lettuce

Grilled Vidalia Onions, recipe follows

Dill pickles, sliced (optional)

Ketchup

Directions:

Divide the beef into 8 (4 oz) burgers. Season on both sides with salt and pepper, to taste. Grill or cook in the skillet for 3 to 4 minutes on each side for medium-rare doneness. During last minutes of cooking add 2 slices of cheese to each burger, cover grill and let melt, approximately 1 minute. Place burger on bun and top with Horseradish Mustard, lettuce, Grilled Vidalia Onions, pickles and ketchup.

Horseradish Mustard:

1/2 cup Dijon mustard
2 tablespoons prepared horseradish

Whisk mustard and horseradish together in a small bowl.

Grilled Vidalia Onions:

2 Vidalia onions, sliced crosswise, ¼ inch thick slices

2 tablespoons olive oil
Salt and freshly ground pepper

Brush olive oil on both sides of the onion and season with salt and pepper. Grill the onion slices for 3 to 4 minutes on each side until golden brown.