Preheat the oven to 400 degrees. Line a baking sheet with a Silpat mat and coat it with olive oil cooking spray.
Make a dredging station by placing the flour on a shallow plate and seasoning with garlic powder, sea salt, and freshly cracked pepper to taste.
Whisk the milk and egg in a small bowl and season with garlic powder, sea salt, and freshly cracked pepper to taste, until well combined.
Place the panko on a shallow plate and add the lemon zest, fresh dill, garlic powder, sea salt, and freshly cracked pepper to taste; mix until well combined.
Cut the fish into strips.
Dredge the fish by dipping each piece in flour, then in the egg mixture, and lastly in the panko crumbs.
Place the coated fish on the baking sheet. Repeat with the remaining fish.
Spray all the fish with olive oil cooking spray.
Bake the fish sticks for 10 minutes or until cooked through and flaky.
Turn the oven to broil, then cook, watching carefully so they don't burn, for a few minutes, to evenly brown on top.
Serve with the cucumber dill sauce on the side, if desired, along with lemon wedges. Enjoy.