Combine tuna, 1 tablespoon mustard, ginger, green onions, soy sauce and pepper to taste. Form into two 3/4-inch thick patties. Heat oil in a skillet until hot, carefully add tuna patties and sear for four minutes. Meanwhile, split rolls in half and drizzle cut sides with some sesame oil. Whisk together remaining tablespoon mustard with honey. Flip patties and continue to cook five minutes. Place rolls, cut side down, on coolest part of grill to toast. During last minute cooking baste patties with honey mustard mixture. Place patties on toasted buns; top each with cucumber and radish.
Other Notes
Serve with the top of bun askew to see presentation of fish.
