Slaw:
Kosher salt
8 cups finely shredded green cabbage 1 cup distilled white vinegar
1 tablespoon sugar
2 tablespoons yellow mustard seeds
Burger:
1 ½ pounds ground beef sirlion
1 teaspoon onion powder
1 teaspoon garlic powder
1 teaspoon sweet smoked paprika
1 tablespoon Worcestershire sauce
Freshly ground pepper
6 ounces extra-sharp cheddar, shredded
2 cups baby arugula
4 hamburger buns, split and toasted
1 container French’s Fried Onions

In a large bowl, toss 1 tablespoon of kosher salt with the cabbage and massage it until it softens and releases its liquid, about 4 minutes. Drain the cabbage in a colander and rinse it.



Wipe out the bowl. Add the vinegar, sugar, mustard seeds, 1 cup of water and 1 tablespoon of salt. Add the cabbage to the vinegar mixture, toss to coat and place a plate on top to keep it submerged. Let stand at room temperature for 2 hours.



In a medium bowl, combine the ground beef with the onion powder, garlic powder, smoked paprika, Worcestershire sauce and 2 teaspoons each of kosher salt and ground pepper. Knead gently until thoroughly mixed. Form the beef into eight 4-inch patties. Press the shredded cheese into four 2 1/2 -inch disks. Sandwich the cheese disks between the patties. Pinch the edges together to seal.



Heat a grill pan or griddle. Grill the burgers over medium heat until browned on the bottom, about 3 minutes. Flip the burgers, invert a large heatproof bowl over them and cook until medium within and the cheese is melted, about 3 minutes longer.



Mound the arugula on the bun bottoms and top with the burgers. Drain the pickled cabbage and mound some of it on the burgers; reserve the rest of the pickled cabbage for another use. Top with the fried onions and the bun tops and serve.



MAKE AHEAD

The pickled cabbage can be refrigerated in its brine in an airtight container for up to 4 days.