Step 1

Adjust rack to top position and preheat oven to 425 degrees. Wash and dry all produce. Halve, peel, and finely dice onion. Cut potatoes into ½-inchthick wedges. Thinly slice tomato into rounds. Halve, peel, and mince shallot until you have 2 TBSP (4 TBSP for 4 servings). Halve buns.

Step 2

Toss potatoes on a baking sheet with a drizzle of oil, ¾ tsp garlic powder (1½ tsp for 4 servings; you’ll use the rest in the next step), salt, and pepper. Roast on top rack until browned and crisp, 20- 25 minutes.

Step 3

Meanwhile, in a small bowl, combine minced shallot, vinegar, 1 tsp sugar (2 tsp for 4 servings), and a pinch of salt. In a separate small bowl, combine ketchup, mustard, sour cream, remaining garlic powder, and 1 tsp sugar (2 tsp for 4).

Step 4

Heat a drizzle of oil in a large pan over medium-high heat. Add onion and cook, stirring occasionally, until browned and softened, 5-7 minutes. Season with salt and pepper. Transfer to a plate.

Step 5

While onion cooks, form beef into two patties (four patties for 4 servings), each slightly wider than a burger bun. Season generously with salt and pepper. Heat a drizzle of oil in pan used for onion over medium-high heat. Add patties and cook almost to desired doneness, 3-5 minutes per side. Top each patty with cheddar and cover pan until cheese melts and patties are cooked to your liking, 1-2 minutes more.

Step 6

While cheese melts, toast buns until golden brown. Drain pickled shallot, discarding liquid. Stir shallot into bowl with sauce. Fill toasted buns with patties, onion, tomato, and sauce. Serve with potatoes and any remaining sauce on the side for dipping.