A simple, versatile dessert.
Place the rhubarb in a large saucepan and add the sugar, salt, and 2/3 cup water. Bring to a boil over high heat, then lower the heat and simmer for about 10 minutes, stirring occasionally, until the rhubarb is tender and starts to fall apart. Remove from the heat, stir in the strawberries, raspberries, lemon juice, orange juice, and orange liqueur, if using, and allow to cool. Serve warm, at room temperature, or cold with a dollop of whipped cream or a scoop of ice cream.