Grate zucchini, wrap in clean dish towel and squeeze out as much liquid as possible. Toss in medium bowl with chopped onion, salt, pepper, garlic powder, red pepper flakes, and besan (chickpea flour). Heat a small amount of oil in pan (to a depth of 1/2 inch or so) and pan-fry until golden (about 1-2 minutes per side). Drain on paper towels and pat to remove excess oil.
While frying make dip: stir together yogurt, finely chopped cucumber, finely chopped mint, lemon juice, and a little salt.
Serve with lots of dip and extra lemon wedges if desired.