Spoon shredded zucchini onto a piece of cheesecloth or a fine mesh strainer (a clean dish towel will do in a pinch) and squeeze out as much liquid as possible. The dryer the better.
In a bowl, mix together zucchini, egg and spices. Strain again.
Divide zucchini mixture in half and form into balls. Flatten balls with a spatula.
On medium-high heat, spritz a pan with cooking spray and add zucchini. Cook until brown, a few minutes per side.
Serve with a dollop of Greek yogurt and chives, if desired.