Coarsely shred zucchini and onion. Toss with 1/2 teaspoon salt and set aside. Cut corn kernels off the cob.

After 10 minutes, wrap the zucchini and onion mixture in a kitchen towel and squeeze out as much liquid as possible.

Combine drained zucchini and onion with corn in a large bowl. Add egg, flour, salt, pepper and cilantro. Mix well.

Heat oil in a skillet over medium heat. Put spoonfuls of the mixture into the skillet and press down with a spatula to flatten. Cook for three to four minutes on each side.

Drain on a paper towel-lined plate. Repeat with remaining batter.

To make sauce, combine all ingredients until smooth. Serve with fritters.