Servings: 2 for dinner, 4 as an appetizer

Creamy Ginger Soy Dressing and Dipping Sauce ( source ): subheading: Creamy Ginger Soy Dressing and Dipping Sauce ( source ):
3 Tbsp white balsamic wine vinegar 3 Tbsp white balsamic wine vinegar
1½ Tbsp soy sauce 1½ Tbsp soy sauce
1 tsp sesame oil 1 tsp sesame oil
4 Tbsp white sugar 4 Tbsp white sugar
1 clove garlic, pressed or minced fine 1 clove garlic, pressed or minced fine
1 packed tsp gari (sweet pickled sushi ginger), minced 1 packed tsp gari (sweet pickled sushi ginger), minced
½ to 1 tsp cayenne pepper, or to taste ½ to 1 tsp cayenne pepper, or to taste
½ tsp course ground black pepper ½ tsp course ground black pepper
½ tsp black sesame seeds (may substitute white sesame seeds) ½ tsp black sesame seeds (may substitute white sesame seeds)
1 to 1½ cups real mayonnaise 1 to 1½ cups real mayonnaise
 
Asian Five Spice Rub ( source ): subheading: Asian Five Spice Rub ( source ):
3 Tbsp Chinese five-spice powder 3 Tbsp Chinese five-spice powder
1 Tbsp light brown sugar 1 Tbsp light brown sugar
1 Tbsp kosher salt 1 Tbsp kosher salt
1 tsp cayenne pepper, or to taste 1 tsp cayenne pepper, or to taste
½ tsp garlic powder ½ tsp garlic powder
 
2 Ahi tuna steaks, approximately 5 oz and 1¼ inch thick each, thawed if frozen 2 Ahi tuna steaks, approximately 5 oz and 1¼ inch thick each, thawed if frozen
1 to 2 tsp neutral oil, such as canola or vegetable oil 1 to 2 tsp neutral oil, such as canola or vegetable oil

Creamy Ginger Soy Dressing and Dipping Sauce: subheading: Creamy Ginger Soy Dressing and Dipping Sauce:
In a small blender (i.e.: Magic Bullet) blend first nine ingredients until smooth. Fold in mayonnaise until thoroughly mixed. Store tightly covered until ready to use, up to three days.
Seared Ahi Tuna: subheading: Seared Ahi Tuna:
Mix five spice rub ingredients and place in small flat bottomed container.
Slice steaks into blocks so that each block is as wide as the thickness of the original steak (the cross section will be a square). Try to slice so that the grain of the fish goes across the short sides of the fish.
Roll each block in the rub so all long faces are covered.
Heat a skillet or griddle until very hot, then add a small amount of oil and swirl or brush it around until the surface has an even layer.
Before the oil starts to smoke place the tuna blocks on the griddle. Sear each face of the block for no more than 45 seconds: you want only about 1/16th of an inch of each surface to be seared, with the rest of of the block remaining deep red.
Rest the blocks of tuna for a couple of minutes, then slice the blocks into 3/16th inch slices across the short sides.
Place tuna on serving plates and serve with dipping bowls of ginger soy dressing. Include extra gari on the side if desired.