Ingredients

2 sweet potatoes (1 pound total), scrubbed and cut crosswise 1/8 inch thick (about 4 cups)

3 cloves garlic, minced (1 tablespoon)

1 shallot, thinly sliced (1/2 cup)

5 tablespoons extra-virgin olive oil, plus more for drizzling

Kosher salt and freshly ground pepper

1 bunch spinach, tough stems removed (6 ounces; 6 lightly packed cups)

4 skinless sea-bass fillets (each 6 ounces), patted dry

2 tablespoons flat-leaf parsley leaves, chopped

2 tablespoons salt-packed capers, rinsed, drained, and chopped

1 tablespoon white-wine vinegar

Preparation

Preheat oven to 425 degrees. Toss sweet potatoes, garlic, and shallot with 2 tablespoons oil. Spread evenly on a rimmed baking sheet and season with salt and pepper. Roast until tender, 25 to 30 minutes.

Remove from oven. Drizzle spinach with oil and season with salt and pepper; scatter over sweet-potato mixture. Season fish with salt and pepper; place on top of spinach. Drizzle fish lightly with oil; roast until opaque and flaky, about 12 minutes. Stir together parsley, capers, remaining 3 tablespoons oil, and vinegar. Drizzle mixture over fish and vegetables; serve.