Chop each of the ends off the zucchini and grate it straight into a clean tea towel. Twist the zucchini up in the towel and squeeze several times over the sink to extract as much of the liquid as possible. Set the zucchini aside.
If using frozen corn, ensure it's defrosted and also pat this dry with paper towel or a clean tea towel. No need to do this with fresh corn.
In a large bowl mix together the two flours, baking soda and salt, then mix well to combine.
Next add in the egg and milk and stir to make a batter. Don't worry if it's not liquid, it shouldn't be.
Now toss in the lime zest, sumac, pepper, mint, garlic, corn, zucchini, and shallots/spring onions/scallions. Stir well to combine so the whole mixture has formed a thick batter.
Add 2 tablespoons of olive oil to a frying pan over medium heat. Do not add the batter before the oil is hot enough! This can lead to soggy fritters and they'll also stick to the pan.
Take 1/4 of a cup of the batter (or a large ice cream scoop) and pour it into the oil. Flatten it out with the back of a spoon so it's thin and round. Repeat with 1 or 2 more fritters, or as many as is suited to your pan. Cook for 3.5 - 4 mins per side - or until golden - then remove to a plate with paper towel to drain any excess oil. Once this batch is complete, repeat the process.
Keep each batch warm in the oven until they're all complete. I do this by sitting them directly on the oven rack, which ensures they don't go soggy. I had my oven on 100ºC/250F.
Serve with your toppings of choice.