Preheat the oven to 425 degrees F.
In a bowl, mix together 3 tbsp of olive oil, 3 tbsp of lemon juice and 1 tbsp of melted butter. In a separate bowl, mix together the flour, dried dill, garlic powder, paprika, salt and pepper.
Dip each individual cod filet into the oil butter mixture, and then into the flour mixture, coating on all sides. Make sure to reserve the left over butter, oil and lemon mixture.Heat 2 tbsp of olive oil in a large cast iron skillet until hot. Carefully add the cod to the pan. Sear on each side until golden, about 2 minutes per side. Remove from the heat.
Add the reserved butter, oil and lemon mixture to the pan. Top the fish with the olives, tomatoes, red onion and parsley.
Bake for 15-25 minutes, depending on the thickness of your fillets. When the fish registers 145 degrees F on an instant read meat thermometer at it's thickest part, it's ready! Top with crumbled feta cheese and serve!