Prep-
Adjust rack to top and pre heat oven to 425 degrees.
Wash potatoes and slice in 1/2 inch wedges.
Halve, peel, and thinly slices onion.

Potatoes-
Lightly oil a baking pan and toss potato wedges on with some old bay seasoning, salt, and pepper.
Roast on top rack until brown and crispy 20-25 minutes.

Onions-While potatoes roast, heat a large drizzle of oil in a medium pan over medium heat.
Add onions and cook until brown (stir occasionally).
Add 2 tsp sugar and a splash of water, cook until onions are caramelized and jammy, season with salt and pepper.
Transfer to a small bowl.

In another small bowl combine 1 tbsp mayo, 1 tbsp ketchup, 1 tsp Dijon mustard and 1 tsp old bay seasoning.
Mix well and set aside.
Form beef into equals size balls and season.

Heat a drizzle of oil in a pan used for onions over medium heat.
Once oil is hot in pan add beef ball and firmly flatten each ball with a spatula to create very thin patties.
Cook for 5-6 minutes each side, then top with white cheddar cheese.