Step 1

Put a rimmed baking sheet in the upper third of the oven and preheat to 475 degrees F. Toss the Brussels sprouts, carrots, red onions, bacon, thyme leaves, 2 tablespoons olive oil, 1/2 teaspoon salt and a few grinds of pepper in a large bowl. Spread on the hot baking sheet and roast until the vegetables are tender and start browning around the edges, about 20 minutes.

Step 2

Season the cod all over with salt and pepper and brush with the remaining 1 tablespoon olive oil. Arrange the cod fillets about 2 inches apart on top of the vegetables and top each with a thyme sprig. Roast until the fish is just cooked through and the Brussels sprouts are browned, 8 to 10 minutes. Discard the thyme sprigs. Sprinkle the cod and vegetables with the parsley and serve with lemon wedges.