In a small saucepan combine strawberries and sugar, and cook at a hard boil for 6 minutes. Mix brandy and cornstarch to a smooth paste. Add to strawberry mixture, stirring constantly; it will thicken instantly. Cook for 2 more minutes. Pour into tart shells. Cool in refrigerator for 1 hour. Garnish with a few strawberry slices, a dollop of whipped cream and mint sprigs.