In a small bowl, combine black and white sesame seeds and Rancher Rub. Brush the tuna steaks with Natural Grapeseed Oil on all sides. Roll the tuna steaks in the sesame seed mixture to coat on all sides.
Heat remaining 1 tablespoon of Natural Grapeseed Oil in a 10-inch nonstick skillet over medium heat. Sear the tuna for 2 minutes on each side. Remove from heat.
In a large bowl, combine the spring mix, cucumber, and radishes. Add Asian Ginger Plum Dressing and toss to coat.
Divide the salad between four plates. Slice the tuna into thick slices serve on top of salad.
