To make blueberry sauce, combine 1 cup of the blueberries, white grape juice, and honey in a medium saucepan. Heat until just bubbly around edges. Cool slightly. Transfer to a blender and blend until smooth. Transfer to a serving bowl, and add remaining blueberries. Makes about 1 2/3 cups sauce. In a medium bowl combine all together flours, walnuts, baking powder, and baking soda. In a separate large bowl, beat the egg whites with an electric mixer until very foamy. Stir in buttermilk and oil. Gradually add flour mixture, beating by hand until smooth. Bake waffles according to manufacturer's instructions. Serve warm waffles with blueberry sauce.
Ready in 30 min