Citrus Rosemary Sauce

• 1 cup orange juice, (from 2-3 oranges)
• 2 tablespoons finely chopped shallot, (1 medium)
• 1 tablespoon chopped fresh rosemary
• 2 teaspoons butter
• 1 teaspoon balsamic vinegar
• 1/4 teaspoon salt, or to taste
• Freshly ground pepper, to taste

Combine orange juice, shallot and rosemary in small saucepan; bring to a boil over medium-high heat. Cook, uncovered, until reduced to 1/2 cup, 6 to 8 minutes. Remove from heat. Add butter, vinegar, salt and pepper; stir until the butter has melted. Serve warm.