Add the cod fillets over some paper towels and pat completely dry, season with salt & pepper on both sides, then cut each fillet into fish sticks that are 3 1/2 inches long x 3/4 inch thick (8 cm x 2 cm), add the fish sticks into a large bowl, along with the flour, gently mix together until all the fish sticks are well coated in the flour
Crack the egg into a bowl, add in the water, season with salt & pepper, and whisk together, add the breadcrumbs into a separate bowl, along with the garlic powder, onion powder, and paprika, and mix together
Heat a large fry pan with a medium heat and add in the sunflower oil
While the oil is heating, coat the fish sticks, first in the egg wash and then in the breadcrumbs, making sure at each stage that they're fully coated all around
Once the oil is nice and hot, about 6 to 8 minutes, add in the fish sticks, all in a single layer and evenly spaced out (cook in batches), fry for 3 minutes per side or until golden and crispy, then transfer over a wire rack with paper towels underneath
To make the dipping sauce, add the Greek yogurt into a bowl, along with the dijon mustard, chopped onion, chopped dill pickels, lemon juice, and season with salt & pepper, whisk together
Add the dipping sauce into a serving dish and decorate the fish sticks around it, enjoy!