Wash and dry all produce. Adjust rack to center position and preheat oven to 425 degrees. Thinly slice pickle; mince a few slices until you have 1 TBSP. Finely grate 1 clove garlic (use the other as you like). Halve and peel onion. Thinly slice one half; grate other half until you have 2 TBSP (save the rest for another use). Slice tomato into rounds.

Cut sweet potatoes into 3-inchlong and 1/2-inch-thick wedges. Toss on a baking sheet with a large drizzle of olive oil, 1 TBSP fry seasoning (save the rest for step 4), and a few large pinches of salt and pepper. Roast in oven until tender and browned, about 20 minutes.

Meanwhile, zest 1/2 tsp zest from lime and place in a small bowl. Halve lime and squeeze 1 tsp juice into same bowl, then add mayonnaise, sour cream, minced pickle, and 1/2 tsp sugar. Stir to combine. Add sriracha to taste (it’s spicy). Season with salt and set aside.

In a large bowl, mix together beef, grated garlic, grated onion, remaining fry seasoning, and a few large pinches of salt and pepper. Divide into 8 pieces and shape each into a thin, flat patty that’s 21/2- to 3-inches wide.

Heat a large drizzle of olive oil in a large pan over high heat (use a nonstick pan if you have one). Add 4 patties and cook until just browned, about 2 minutes per side. Transfer to a plate. Add remaining patties to pan and cook until just browned on bottom, about 2 minutes. Flip, top each with a cheddar slice, then place cooked patties on top. Cook until bottom patties are done and cheese melts, about 2 minutes more.

Split buns in half. (TIP: You can toast them in a toaster or in the oven, if you’d like.) Spread a little bit of sauce onto top halves of buns. Place stacked patties on bottom halves of buns, then top with tomato, sliced onion, and sliced pickle. Serve with sweet potatoes on the side and remaining sauce for dipping.