6 small tomatoes, seeded and cut into 1/2-in. pieces
1/2 cup balsamic vinegar
Preheat oven to 450°. Rub 1 teaspoon oil over both sides of salmon; sprinkle with seafood seasoning and pepper. Place in a greased 15x10x1-in. baking pan; roast until fish just begins to flake easily with a fork, 10-12 minutes.
Meanwhile, place remaining oil, garlic and pepper flakes in a 6-qt. stockpot; heat over medium-low heat until garlic is softened, 3-4 minutes. Increase heat to medium-high. Add spinach; cook and stir until wilted, 3-4 minutes. Stir in tomatoes; heat through. Divide among four serving dishes.
In a small saucepan, bring vinegar to a boil. Cook until vinegar is reduced by half, 2-3 minutes. Immediately remove from heat.
To serve, place salmon over spinach mixture. Drizzle with balsamic glaze.
Health tip: This dish is easy enough for weeknights, but special enough for company, especially if any guests eat gluten-free. Test Kitchen tips
Serve this dish in shallow bowls with French bread to soak up the flavorful juices.
Ten cups of spinach sounds like a lot, but it wilts down to just 3 cups after it's cooked.