Start making your kolokithokeftedes by placing the grated zucchini in a colander and sprinkle salt on it; use a fork to mix.
Let it sit for 30 to 60 minutes to eliminate the liquid. (Note: Make sure you place a bowl under to catch the water.) Heat the olive oil over medium heat using a medium-sized pan or skillet.
Add finely chopped onion, and cook until it softens, then set aside to cool.
Take the zucchini out of the colander and use your hands to squeeze the remaining liquid in them.
Combine zucchini, flour, baking powder, egg, pecorino Romano, dill, breadcrumbs, pepper, and the cooled onion in a separate bowl.
Use a fork to mix everything evenly.
Take a spoonful of the zucchini fritters mixture and shape it.
Heat the vegetable oil in a medium-sized pan over medium-high heat.
Once the oil is ready, add the zucchini balls carefully.
Cook until all sides of kolokithokeftedes are golden.
Place them on kitchen paper to absorb excess oil.
Serve and enjoy your kolokithokeftedes!