Zucchini and Turkey Burgers

This recipe is adapted from Ottolenghi's Jerusalem - an absolutely gorgeous cookbook!  Don't expect these to be the kind of burgers you can throw on the grill; they have to be cooked in a pan and handled gently and lovingly.  They go nicely with a parsley salad and if you can get (or make) some nice naan or pita bread, then you've entered into food nirvana. A pretty rosé complements this meal.
Burgers:
1 lb ground turkey
1 large zucchini, coarsely shredded and drained in a colander for about 30 min.
3 green onions, chopped
1 egg, beaten
2 T cilantro, chopped finely
2 cloves of garlic, pressed
1/2 t cumin
1/2 t turmeric
1 t kosher salt
freshly ground pepper
1/4 t cayenne pepper (or more if you want it spicier)

Sumac Sauce:
1/2 cup sour cream
2/3 cup Greek yogurt
1 t lemon zest
1 T lemon juice (freshly squeezed, goes without saying right??)
1 clove of garlic, pressed
1 T sumac (available at ethnic-type stores)
1 1/2 T extra-virgin olive oil
1/2 t salt
freshly ground pepper
For the sauce: Mix all ingredients together. 

For the burgers: squeeze out the zucchini a bit just so it's not too watery and mix it with the rest of the ingredients.  I formed this concoction into 5 patties (almost kind of scooping them out) onto a wax paper lined baking sheet and then refrigerated them for about 1/2 hour to firm up a little.  Fry them over medium-high heat for 4 minutes per side (exactly and approximately) in olive oil. Serve with a little dollop of sauce.
I suppose if you want it to be super-healthy, you can use all Greek yogurt. It won't have quite the richness but would still be delicious I'm sure.