In a medium saucepan combine strawberries, blueberries, orange juice, and sugar. Cook over medium heat for 4 to 5 minutes or just until bubbly, stirring occasionally. Remove from heat. Let stand about 5 minutes to slightly cool the mixture.
Ladle the soup into 4 shallow dessert bowls. Top each with a scoop of sorbet. If desired, garnish with fresh mint.