Blueberry Shortcakes with Strawberry Ice Cream

FOR THE BLUEBERRY MIXTURE:
Combine 3 cups of blueberries, 1/2 cup of water and sugar in medium, nonreactive saucepan. Bring to simmer. Cover partially and cook over medium heat until very juicy, about 3 minutes.

Meanwhile, gradually stir remaining 1/4 cup water into cornstarch in small bowl. Stir cornstarch mixture into cooked berries. Simmer until thick, about 2 minutes. Remove from heat. Stir in butter. Cool to room temperature. Stir in remaining 3 cups blueberries and lemon juice. The berry mixture can be made up to 1 day ahead (it will thin slightly upon standing but will still taste good). Cover and chill, returning mixture to room temperature before using.

TO ASSEMBLE:
Split hot shortcakes in half horizontally, setting bottoms in wide shallow dessert bowls. Spoon about 1/2 cup of blueberry mixture over each shortcake bottom. Set tops in place. Set a small scoop of ice cream beside each shortcake. Spoon about 1/4 cup more blueberry sauce over each shortcake top. Serve immediately.