For the dressing: In a bowl, whisk together the mayonnaise, catsup, relish, vinegar, celery seed and hot sauce, mixing well. Then blend with the sauerkraut and hold.
For the burgers: Preheat a grill to 350 degrees F.
In a bowl, blend the beef, corned beef and pork by hand, mixing well until evenly and thoroughly mixed. Next, portion the meat into 4 equal patties and sprinkle evenly with salt and pepper on both sides. Grill the burgers on the first side for 5 to 6 minutes, then flip and repeat grilling on the second side.
While the burgers are cooking, in a saute pan over high heat, add grapeseed oil, allow to heat until smoking then reduce the heat to medium. Next, add the dressed sauerkraut and cook until browned, 3 to 4 minutes, stirring with a spatula during the process. Once cooked, add one-quarter of the dressed kraut on the top of the burgers, and then top with the cheese.
To build the burgers: Heat a pan over medium-high heat, add the butter to the pan and brown the rolls one at a time, repeating the process until all the rolls have been browned. Then place the dressed burgers on the bottom buns, finish with the bun top and serve.
Recipe courtesy of Robert Irvine