Prepare Creme Fraiche. In a glass jar combine the sour cream and heavy cream. Let sit at room temperature until ready to serve. Just before serving, stir in ground ginger and lime zest.
In a separate bowl, combine mayonnaise, eggs, lime juice, fresh ginger, and honey. Add tuna, coconut, and bread crumbs. Mix well and then shape into croquettes. Fry in coconut oil. Add more oil if needed. Drain on paper towels. Serve croquettes with a dollop of Ginger Lime Creme Fraiche. Garnish with a slice of lime.