Preheat a grill to medium heat. (If using a grill pan, you’ll heat it in Step 3.)

Wash and dry produce.

Halve potatoes lengthwise.

In a large microwave-safe bowl, toss potatoes with a pinch of salt. Cover tightly with plastic wrap; microwave until potatoes are fork tender, 5-8 minutes. (For 4 servings, you may need to microwave potatoes for an additional 2-3 minutes.)

Add a drizzle of oil and season with pepper; toss to combine.

While potatoes cook, finely chop half the pickle slices. (If using a grill pan, heat over medium-high heat while potatoes cook.) Trim and thinly slice scallions.

In a small bowl, combine mayonnaise, ketchup, and chopped pickle. Set aside.

Add microwaved potatoes to grill (or grill pan), cut sides down; grill, flipping occasionally, until lightly charred, 2-3 minutes. Wash and dry bowl.

Season potatoes with salt and pepper. Transfer to a plate.

Meanwhile, in bowl used for potatoes, combine beef*, garlic powder, salt (we used ½ tsp; 1 tsp for 4 servings), and pepper.

Form mixture into two patties (four patties for 4), each slightly wider than a burger bun. Brush patties all over with a drizzle of oil.

Add patties to grill (or grill pan); grill to desired doneness, 3-5 minutes per side (grills can vary).

In the last minute of grilling, top each patty with cheddar.

Meanwhile, halve buns; toast until golden.

Spread cut sides of buns with as much sauce as you like. Fill buns with patties.

Divide burgers and potatoes between plates. Top potatoes with sour cream and garnish with scallions. Serve with remaining pickle slices and any remaining sauce on the side.