Walleye With Roasted Grapes and Fingerling Potatoes
1 pound small fingerling potatoes
4 tablespoons olive oil, divided
Kosher salt and freshly ground black pepper
10 ounces tart red seedless grapes
4 walleye or other white fish fillets such as cod, haddock, or tilapia, about 6 ounces each
1 medium clove garlic, thinly sliced
1 lemon, half left whole, half thinly sliced
Adjust oven rack to middle position and preheat oven to 450°F. Add potatoes to a rimmed 12- by 18-inch baking sheet and drizzle with 2 tablespoons olive oil and season with a pinch of salt and pepper. Toss until evenly coated. Transfer sheet to oven and cook for 10 minutes.
Carefully remove sheet pan from oven, and use a pair of tongs to move the potatoes to one end. Drizzle a tablespoon of oil over the empty end, and then add the grapes and the walleye fillets skin-side down. Season each fish fillet with a pinch of salt and pepper, and then top with few slices of garlic and a couple slices of lemon. Drizzle remaining tablespoon of olive oil over the fish.
Return the sheet pan to the oven and cook until fish is fully cooked and potatoes are tender, 10 to 12 minutes.
Divide the fish, grapes, and potatoes between four plates. Squeeze some juice from the uncut lemon half over each plate. Serve immediately.