• 4 mandarin oranges or tangerines
• 3½ tablespoons unsalted butter
• 1 pound branzino fillets, sliced crosswise into 1-inch-wide pieces
• Salt
• Freshly ground black pepper
• 1 teaspoon sugar
• 2 tablespoons fresh lemon juice
• Fresh dill for garnish

Juice 2 of the mandarins; set juice aside. Peel remaining mandarins, reserving one peel. Separate mandarins into sections.

In a large nonstick skillet, heat butter with mandarin peel over medium-high heat. When butter begins to bubble, add half of the fish, skin-side down. Cook for 1½ minutes, then turn, season with salt and pepper, and cook until fish is cooked through, about 1½ minutes more. Transfer fish to paper towels to drain. Repeat with remaining fish. Discard peel.

Add sugar to pan; whisk to combine with butter and return pan to medium heat. Cook until sugar begins to caramelize, about 1 minute. Add reserved mandarin juice and lemon juice; whisk to combine. Add mandarin sections, bring to a simmer and cook, stirring to combine, for 30 seconds. Divide sauce among serving plates; top with fish and sprinkle with dill.