1 large Vidalia, Maui or other sweet onion, peeled and sliced into rings 1/2-inch thick
2 cups buttermilk
Canola oil, for frying
1 cup flour
1/4 cup cornmeal
2 pounds ground sirloin
2 tablespoons chili powder, preferred brand Gebhardt
1 tablespoon smoked sweet paprika
3 tablespoons grated onion
2 cloves garlic, grated or pasted
2 tablespoons Worcestershire sauce
2 tablespoons brown or yellow mustard
Kosher salt and pepper
1/2 cup ketchup
3 tablespoons Sriracha
4 pretzel rolls (I get mine from Whole Foods)
Chopped or shredded iceberg lettuce
Combine the onions and buttermilk, and refrigerate 8-12 hours.
Heat oven to 250°F.
Heat a few inches of oil to 350°F or set up a tabletop fryer. Combine flour and cornmeal and toss in O-rings to coat. Add to the hot oil and fry 3 minutes to golden. Season with salt and drain on paper towels. Keep warm in oven on a wire rack set onto a baking sheet.
Combine meat and spices, grated onion, garlic, Worcestershire, mustard, salt and pepper. Form 4 patties thinner at center and thicker at edges for even cooking.
Heat a cast-iron skillet over medium-high heat. Combine ketchup and Sriracha sauce in a small bowl.
Brush pretzel buns with a little water and sprinkle with the salt included in the package. Warm pretzel buns in the oven for 5 minutes and split them open.
Cook burgers in the hot skillet for 8 minutes, turning once.
Serve burgers on a bed of shredded lettuce topped with 2-3 crispy rings and some spicy ketchup.