Turn the tuna through a meat grinder so that the finely pureed fish substance remains. Then put the fish in a bowl.
Chop the ginger, garlic and onions very finely and add to the bowl with the egg and the spices (spices as desired, best to taste in between!). Knead the whole thing well with a hand blender. Then shape the meatball size by hand and arrange on a plate.
Serve with cocktail tomatoes and hot pepperoni. Enjoy the tartare drizzled with soy sauce.