Mix the mayonnaise, capers and Wasabi Mustard together. Set aside.
For the wontons:
Stovetop method: Cut 15 wonton wrappers into two pieces. Heat 1/2 cup oil in a skillet over medium-high heat until it shimmers and is almost to the smoke point. Add the wonton pieces a few at a time and fry until golden brown on both sides. Remove and place on a paper towel.
Oven method: Brush sesame oil on a baking sheet. Place cut wontons on the sheet. Brush tops of wontons with oil. Bake in a preheated 350 degree F. oven until crisp and golden, about 10 minutes.
For the tuna:
Pour 1/4 cup Sesame Ginger Teriyaki Sauce and 2 Tablespoons sesame oil into a bowl.
Mix Well. With a pastry brush, coat both sides of the tuna steaks and sprinkle with salt and pepper.
Heat a sauté pan on medium high for 3 to 4 minutes. Sear the tuna steaks for 3 minutes on each side or until outside is golden and middle is still pink. Remove from heat.
Putting it all together:
Slice the tuna on the bias, into about 15 slices per steak. Put a slice on each wonton half, top with a dollop of tartar sauce and garnish with chives.