For Mango-Orange Relish: In a medium bowl, combine the mango, oranges, roasted red sweet pepper, orange juice, wine and cilantro. Chill, covered, for 2 to 4 hours before serving.
Meanwhile, thaw fish, if frozen. Rinse; pat dry. Preheat oven to 300°. On a sheet of waxed paper or in a shallow dish, combine flour and cardamom. Coat both sides of each fillet with the mixture; shake off excess flour.
In a 12-inch, preferably nonstick skillet, melt 2 tablespoons of the butter. Add two or three of the fillets in a single layer. Cook fish over medium-high heat for 2 to 4 minutes or until golden brown. Turn carefully. Cook about 4 minutes more or until golden and fish flakes easily with a fork. Drain on paper towels. Keep warm in the oven while cooking remaining fish in remaining butter. Serve fish topped with Mango-Orange Relish and chives.