Instructions Have fish seller cut tuna steaks in 3/4" thickness. If desired, swordfish or shark may be substituted for tuna. Mix wasabi powder and lemon juice together to a thin paste consistency, adding more or less of each ingredient until desired thickness is reached. Let stand ten minutes

Cut the tuna into 2 inch logs, 1 1/2 inches wide and 1 1/2 inches thick. Season the tuna with salt and pepper. In a small bowl, whisk the wasabi and water together to form a loose paste. Using the potato threader, cut the potato into thin curl-like pieces. Season the potatoes with salt and pepper.

I tried this recipe tonight and it is wonderful!