3/4 cup water
1/2 pound trimmed rhubarb (8 ounces, thinly sliced and coarsely pureéd in a food processor)
1/2 pound ripe strawberries (8 ounces, thinly sliced and pureéd in a food processor)
3 tablespoons fresh lemon juice
1 cup ginger snap crumbs (from 5 ounces of cookies)
2 tablespoons melted unsalted butter
1 cup Sugar
5 tablespoons water
4 large egg whites, at room temperature
1/4 teaspoon salt
    Fresh mint sprigs, as garnish (optional)
8   ripe strawberries, as garnish (optional)
1/4 cup Sugar