Preheat a deep pot of oil or a deep fryer to 325 degrees F.
In a bowl, combine the tuna, green onions, ginger, wasabi, sesame oil, soy sauce and lime juice, and mix until well blended. Taste and adjust seasoning with lime juice or soy sauce. Set bowl over ice.
Deep-fry the potato gaufrettes until crisp and golden. Drain onto a paper towel lined plate and season with salt.
Place a spoonful of the tuna tartare on one end of each potato gaufrette. Repeat process until you have enough to arrange on a serving platter. Serve immediately.