Heat oven to 400 F.

In large saucepan, place potatoes and cover with water. Bring to boil and heat until potatoes are just barely fork tender. Drain well. Alternatively, place potatoes in steamer basket set over 2 inches water and steam until just barely fork tender.

Place potatoes in large bowl and toss with 1 Tbsp oil, Italian seasoning, and 1/4 tsp salt. Spread out on rimmed baking sheet and cook in preheated oven until crispy, about 35 minutes, stirring once halfway through cooking.

In large shallow dish, mix flour, paprika, garlic powder, 1/2 tsp salt, and black pepper together. Dredge both sides of perch fillets in flour mixture.

Heat large skillet on medium high. Add butter and remaining 2 Tbsp oil; heat until butter foams vigorously. Carefully add fillets, skin side down. Fry for 2 to 3 minutes, or until skin is well browned. Turn fish over and cook another 1 minute, or until just cooked through. Do this in batches if needed.

To make parsley sauce, in blender or mini food processor, blend together olive oil, 2 Tbsp water, lemon juice, garlic, parsley, and salt until smooth.

Place perch and potatoes on serving plates and drizzle parsley sauce overtop fish.