To a food processor add the onion and garlic and pulse to chop into small pieces. Add the defrosted shrimp, salt, pepper, bread crumbs, lemon zest, chili flakes, feta cheese and egg. Pulse to chop / combine everything, making sure not to over-mix into a paste .
Pour mixture into a bowl or scoop directly out of the food processor, about 1/4 cup at a time and form / flatten into 1/2 inch shrimp patties.
Add 1 tbsp olive oil to a frying pan and heat over medium heat. Fry for 3-4 minutes per side, until golden brown on each side and the shrimp cakes are cooked through. You'll know the shrimp cake is ready to flip if the spatula can slide underneath the pattie easily. Flip a third time if you think the shrimp cakes need a bit more time to cook.
Fry in batches until all of the shrimp cakes have been cooked. Enjoy dipped the best tzatziki recipe!
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Notes
If you don't have a food processor, you can chop the shrimp into small pea-sized pieces and then mix together in a bowl with all of the other ingredients. Then, form into shrimp cakes and follow the rest of the recipe.