In a skillet, fry bacon until soft cooked. Remove from pan & blot on paper towel. Chop & set aside.
Using bacon drippings, saute finely chopped leeks & garlic until tender. Remove from skillet & cool.
In a large bowl, combine ground turkey, sauteed leeks & garlic, panko, salt, pepper, sugar, coriander, sage & ginger. Mix well.
Shape into (8) 1/2-inch thick patties. Place 1/8 (10 gm) of the crumbled Gorgonzola & 1/4 of chopped bacon on each of 4; top with another patty, pressing edges to seal, making (4) 1-inch thick patties.
Place on a preheated grill over medium heat. Close lid & grill, turning once, until meat is no longer pink inside, about 12-14 minutes.
Alternately, you can place them in a 375 F oven on a foil-lined tray & bake for about 20-25 minutes.
When burgers are almost done, top each with remaining Gorgonzola.
Serve in toasted ciabatta buns with your choice of toppings.