Berry-Citrus Trifle

In a glass bowl, whisk eggs, juice, zest and 1/4 cup sugar. In a medium saucepan, bring 2 inches of water to a boil. Reduce heat to medium-low and set bowl over pan. (Bottom of bowl should sit above the water without touching it.) Cook egg mixture, stirring occasionally, until thick enough to coat a spoon, about 20 minutes. Whisk in gelatin until fully dissolved. Remove bowl from heat; pour curd evenly among four 5-ounce serving glasses; refrigerate until solid, about 2 hours. In a small saucepan over medium-high heat, cook berries with remaining 3 tablespoons sugar, stirring occasionally, until berries break down, liquefy and start to bubble, about 10 minutes. In a bowl, strain one third of hot berry mixture; add cornstarch and whisk until fully dissolved. Pour juice-cornstarch mixture into same saucepan; cook over medium-high heat until sauce thickens, about 2 minutes. Remove from heat and stir in chopped mint; let cool completely. Spoon berry sauce evenly over curd. Refrigerate at least 1 hour or up to 24; remove from fridge 30 minutes before serving; garnish with mint sprigs.