Grate 2 medium zucchini on the large holes of a box grater. Place in a colander set over a large bowl. Sprinkle with ½ teaspoon of the kosher salt and toss to combine. Let drain for 15 minutes.

Meanwhile, prepare the following, adding to a large bowl as you go: Finely chop until you have 1 tablespoon fresh basil leaves and 1 tablespoon fresh parsley leaves. Grate 1 garlic clove. Finely grate 2 ½ ounces Parmesan cheese (about ¾ cup). Add 2 large eggs and ½ cup whole milk and mix until well combined.

When the zucchini is ready, press on it with your hands or a wooden spoon to push out some of the liquid. Transfer the zucchini to a clean kitchen towel, wrap it up, and squeeze out as much water as you can to get it as dry as possible. You should have about 1 ½ cups.

Add the zucchini, ½ cup all-purpose flour, ½ cup panko breadcrumbs, remaining ¼ teaspoon kosher salt, and ¼ teaspoon black pepper to the bowl. Stir until a batter just comes together.

Heat 1 tablespoon of the canola oil in a large frying pan or cast-iron skillet over medium heat until shimmering. Drop 4 (¼-cup) portions of the batter into the pan. Press each portion down lightly with the bottom of the measuring cup to flatten slightly. Cook until golden-brown on the bottom, 2 to 3 minutes. Flip and cook until the second side is golden-brown, 2 to 3 minutes more.

Transfer to a paper towel-lined plate. Repeat frying the remaining fritters, adding 1 tablespoon canola oil to the pan between batches. Garnish with flaky salt and more grated Parmesan before serving.