Burger:

1. Preheat your grill or skillet to medium-high heat.
2. Weigh and shape ground beef into a patty. Season both sides of the patty with salt and pepper.
3. Place the patty on the grill or skillet and cook for 1-2 minutes and sear, before flipping add mustard to the patty. Spreading to ensure full coverage.
4. Cook until it reaches your desired level of doneness. During the last minute of cooking, add a slice of cheese and let it melt.

Sauce:

1. Start by dicing the onions and adding unsalted butter to a small saucepan over medium heat.
2. Add in the onions once the butter is bubbling along with a pinch of sugar and salt.
3. Cook over medium heat for 30 minutes.
4. In a medium bowl, combine and whisk together mayo, ketchup, finely chopped chives, worcestershire sauce, and a pinch of salt.
5. Add finely diced dill pickles and caramelized onions. Mix together.

Assembly:

1. Spread the animal style sauce on the bottom half of each bun. Add a patty with melted cheese on top. Finish with the top half of the bun.