Cut the purple cabbage into bite-size pieces. Lightly sauté in a pan with a small amount of salad oil until slightly tender, then let cool.
Thinly slice the purple onion, soak in water, and drain. Peel and segment the grapefruit, removing all membranes. Halve the smoked salmon slices.
Arrange the cabbage, onion, grapefruit, and smoked salmon on a serving plate. Sprinkle with the mixed beans and grains, then drizzle with Kewpie Carrot Dressing.