Greek yogurt—a test kitchen favorite—makes this dinner light and delicious. Everyday Food editor Sarah Carey teaches you how to use this genius ingredient to add flavor to flounder.
Heat broiler, with rack in top position. Combine yogurt, mustard, capers, and 1 teaspoon oil. Season with salt and pepper.
Pat fillets dry with paper towels. Coat one side of fillets with 1 teaspoon oil and arrange, oil side down, on sheet. Spread yogurt mixture on fillets. Broil until fish is opaque throughout and yogurt mixture is bubbling and browned in spots, about 5 minutes. Toss greens with remaining 2 teaspoons oil, season with salt and pepper. Serve fillets with greens and lemon wedges.