Step 1 Mix the sugar and water in a medium stainless saucepan. Dip your hands in water and use them to wipe down the sides of the pot to remove sugar granules and prevent crystallization.
Step 2 Cook the sugar-water mixture without stirring over high heat to a light golden caramel, about 10 minutes.
Step 3Add the brandy and half of the berries to the pan. Reduce the heat to medium and continue to cook until the sugar melts, about 5 minutes. Do not overcook; you want the berries to remain whole.
Step 4Remove from heat and strain the berries over a bowl. Return the juice to the pan and bring to a boil over a high flame. Whisk in the cornstarch slurry. Boil until thickened and clear, about two minutes.
Step 5In a bowl, gently combine the cooked berries, the remaining fresh berries and the thickened juice.