Prepare the Zucchini: Grate the zucchini using the large holes of a box grater. Place the grated zucchini in a colander, sprinkle with kosher salt, and let it sit for about 10 minutes to draw out excess moisture. Afterward, squeeze out the water by pressing the zucchini in a clean kitchen towel.
Combine the Ingredients: In a large bowl, mix the squeezed zucchini with mayonnaise, eggs, diced bread, minced green onions, garlic, lemon zest, and rosemary. Stir until fully incorporated.
Add the Cheese: Stir in the grated cheddar and Parmesan cheeses until evenly distributed throughout the mixture.
Form the Bites: Heat a non-stick skillet over medium heat and lightly grease with oil or cooking spray. Shape the zucchini mixture into small patties or fritters and cook them in batches in the skillet.
Cook the Zucchini Bites: Fry each side for 3-4 minutes until golden brown and crispy. Once done, transfer them to a paper towel-lined plate to remove any excess oil.
Serve and Enjoy: Serve the zucchini bites warm with your favorite dipping sauce, and enjoy the crispy, savory goodness!