Step 1

Combine the coleslaw mix, 2 tablespoons of the minced onion, mayonnaise, vinegar, sugar, celery seeds, garlic powder, pepper, and salt together in a large bowl.

Step 2

Refrigerate the coleslaw until ready to use.

Step 3

In a skillet over medium heat, add 1 pound of the ground beef and cook until browned, about 5-7 minutes.

Step 4

Add the chili seasoning, water, remaining minced onion, and ketchup.

Step 5

Simmer until the chili is thickened and the meat is tender, for about 10 minutes.

Step 6

Gently pat the ground chuck into 4 equal patties, putting a small divot in the center of each with your thumb.

Step 7

Sprinkle the patties with the steak seasoning.

Step 8

In a skillet over medium heat, cook the burgers until heated to at least 145 degrees F internally, about 4 minutes per side.

Step 9

Top the patties with the cheddar cheese and cook until melted.

Step 10

Spread the mustard on the inside of the buns.

Step 11

Place the burgers on the bottom buns and top with the chili, slaw, and diced onions.

Step 12

Close the buns and serve.