Adjust rack to top position and preheat oven to 425 degrees. Wash and dry produce.

Cut potatoes into ½-inch-thick wedges. Pick parsley leaves from stems; discard stems and finely chop leaves. Trim and thinly slice scallions, separating whites from greens; finely chop whites. Quarter lime.

Toss potatoes on a baking sheet with a drizzle of oil, half the garlic powder (you’ll use the rest in the next step), salt, and pepper. Roast on top rack until browned and tender, 20-25 minutes.

While potatoes roast, in a small bowl, combine parsley, scallion whites, remaining garlic powder, 2 TBSP olive oil, 2 tsp vinegar, a pinch of chili flakes, salt, and pepper (4 TBSP olive oil and 4 tsp vinegar for 4 servings). (Save remaining vinegar and chili flakes for another use.) Taste and adjust seasonings as you like.

Set aside, stirring occasionally, until ready to serve.

Pat steak* dry with paper towels and season generously all over with salt and pepper.

Heat a drizzle of oil in a large pan over medium-high heat. Add steak and cook to desired doneness, 5-7 minutes per side.

Turn off heat; transfer steak to a cutting board. Wipe out pan.

Drain corn; pat dry with paper towels.

Heat a drizzle of oil in pan used for steak over high heat. Add corn and cook, stirring occasionally, until golden brown and lightly charred in spots, 3-5 minutes. TIP: If corn begins to pop, cover pan.

Transfer corn to a medium bowl and stir in scallion greens, mayonnaise, half the chili powder, ¼ tsp sugar, a squeeze of lime juice, salt, and pepper (all the chili powder and ½ tsp sugar for 4 servings). TIP: If you like things spicier, add some chili flakes!

Thinly slice steak against the grain.

Divide steak, potatoes, and corn salad between plates. Spoon chimichurri over steak and serve with remaining lime wedges on the side.