How to Make It
Preheat oven to 450°F. Toss potatoes, bell peppers, scallions, and lemon slices with ¼ cup oil, 1 teaspoon salt, red pepper flakes, and oregano sprigs on a rimmed baking sheet. Roast until potatoes are tender and peppers are blistered, 20 to 25 minutes.
Toss shrimp with remaining 1 tablespoon oil and ½ teaspoon salt, plus several grinds of black pepper. Arrange in a single layer on top of vegetables and return to oven. Roast until shrimp are opaque, about 5 minutes.
Serve with lemon wedges.