Cut the fish fillet in sticks, 3-4 inches long and pat them dry with a paper towel.
Prepare three bowls or shallow dishes. One with the flour, one with the milk and yogurt mixed and one with breadcrumbs, garlic powder, oregano, paprika and salt mixed. Line the bowl one next to the other.
Start coating one fish finger in the flour. Tap away the extra flour.
Then dip the fish finger in the yogurt mix so that all the surface is coated. Using a fork to hold the fish finger, shake out the extra yogurt.
Place the fish finger in the breadcrumbs bowl and sprinkle the breadcrumbs all over the fish finger. Pat the breadcrumbs with your fingers to cover all the surface. Place the fish fingers on a plate and keep going with the other fish sticks. Same order: flour then yogurt than breadcrumbs.
Heat the olive oil in a large skillet at medium high and place the fish fingers one next to the other. Cook for 3 min, flip on the other side and keep cooking for additional 3-4 min up until all the sides are nicely golden. Transfer on a serving plate.
Place all the ingredients in a small bowl: avocado, yogurt, salt, garlic powder, lemon juice. With a fork mash and reduce everything to a smooth puree. If you want a velvety dip you can use an immersion blender with a tall container or a small food processor.