These crispy, golden patties can be tucked into a bun for a vegetarian burger substitute, or simply served with a smear of tzatziki and a sprig of mint.
Shred zucchini and squeeze out excess water. Put drained zucchini in a large bowl. Grate the onions and squeeze out excess water. Add onions to bowl with zucchini.
Add mint, dill, kasseri, myzithra, and feta cheeses. Stir to combine.
Stir in eggs and season with black pepper. Stir in flour until dough comes together, adding slightly more flour if dough is too wet to form patties. Form dough into six 3-4 inch patties.
Heat olive oil in a large skillet over medium high heat. Fry patties until golden brown on both sides and cooked through but still moist, about 2-3 minutes per side.
For a healthier option, bake patties on baking sheet at 400ºF until golden brown (25-30 minutes). Mixture can also be used to form cocktail size zucchini bites.