ONION-WRAPPED FLYING DUTCHMAN

1. Make the sauce- by combining all the ingredients together and set aside.
2. Cut the onion into thick circular slices. Portion the ground beef into 4-6 equal pieces (depending on the size you want to make them) form them into balls.
3. Put a large skillet on medium-high heat. Add in oil then the onions and Cook for a few minutes until you see the edges turn golden. Flip over gently and caramelize the other side. Before you take them out of the skillet, add cheese to half the grilled onions.
4. In that same skillet cook the burgers, Add in 2 balls at a time, smash them down into thin patties and season with salt, black pepper and spread about 1/2 teaspoon of mustard on each.
5. Cook until golden brown, about 2 minutes, before flipping.
6. Place the cheese on the patties and when it has melted, stack the burgers on top of each other to create a double burger and continue with the rest.
7. Assemble the burgers- Transfer this stack on top of a grilled onion with cheese and add a grilled onion on top as the bun and devour with the sauce!!