Step 1Shred the zucchini and put it in a colander. Sprinkle generously with salt, mix well and set aside for at least 30 minutes to drain. Toast the cumin and coriander seeds in a small dry skillet over medium heat until they begin to pop and smell fragrant. Grind in a spice grinder or mortar and pestle.
Step 2Rinse the shredded zucchini under cold running water. Pick up a small handful, squeeze it dry and put it in the center of a linen dish towel. When you've squeezed all the zucchini by hand, gather the dish towel around the zucchini and twist, wringing out as much liquid as you can. The more liquid you remove, the lighter the fritter will be.
Step 3Put the zucchini in a bowl and add the green onion, jalapeno, cumin and coriander and stir to mix well. Stir in the flour and then the beaten egg. The mixture should be sticky, but there shouldn't be any free liquid. If there is, stir in a little more flour.
Step 4Pour olive oil into a nonstick skillet to a depth of about one-fourth inch (it'll take about one-fourth cup) and heat it over medium-high heat. When the oil is hot enough that a little bit of zucchini sizzles immediately, drop 4 (2 to 3 tablespoon) mounds of the batter into the pan, flattening them slightly with the back of a spoon.
Step 5Fry until golden brown on one side, 3 to 4 minutes, then gently flip and fry until golden brown on the other side, 2 to 3 minutes. Remove to a paper towel-lined plate and gently pat away any excess oil.
Step 6Serve immediately, with a dollop of thick Greek yogurt.