Preheat the oven to 400°F. Line a baking sheet with parchment paper.

Add 1 teaspoon of the olive oil and the cajun seasoning onto fish. Rub to coat.

Place the Brussels sprouts onto the baking sheet, drizzle with remaining 1 teaspoon of oil. Season with pepper and toss to coat. Bake in the oven for 15 minutes. Remove baking sheet from oven carefully, shake Brussels sprouts to loosen and create a space in the middle of the baking sheet for the fish. Place the fish into the middle, and bake for a further 10 to 15 minutes, or until the Brussels sprouts are tender and slightly brown on the edges, and the fish is cooked through.

Remove fish and Brussels sprouts from the oven and divide between two serving plates. Serve with the corn and lemon wedges.