In 10-inch skillet, melt butter over medium-high heat. Add rhubarb; cook about 5 minutes or until softened. Stir in strawberries, granulated sugar, almond extract, vanilla and lemon juice. Cook about 7 minutes or until mixture begins to thicken slightly. Remove pieces of rhubarb; discard. Pour remaining portion into blender. Cover; blend with on-and-off pulses until smooth. Set sauce aside.