In a small bowl, combine kosher salt, granulated onion, granulated garlic, coarse black pepper and celery salt. Mix thoroughly, season burgers and place them on the grill. Cook to desired doneness (medium well is 155 degrees). After flipping burgers, add cheese slice(s) if desired, and season other side with seasoning salt.
In a large cast-iron Dutch oven or pot, heat vegetable oil for deep frying.
Carefully drop frozen French-fried potatoes. The ice on the potatoes may cause the hot oil to pop and spatter. Cook fries to desired doneness. Drain on paper towels and sprinkle seasoning salt to taste.
In a saucepan, heat 1 tablespoon butter. Add sliced yellow onion rings and saute until browned. Season with salt and pepper.
Place hamburger buns on grill to toast. Place your favorite cheese or cheese slices on burgers to melt.
To assemble the burger, place the burger on the toasted bun. Place sauteed onions over the burger before covering it with the top part of the bun. Arrange hot fries next to the burger. Garnish with lettuce leaves, red-onion slices, tomato slices and bean sprouts. Serve immediately.
Note time is not accurate because of the need to cook to temp not to time.