In a medium size saucepan, heat 3 tablespoons of olive oil over medium-high heat and cook the onions, garlic, tomato and capers for 5 minutes. Add the lemon juice then swirl in the butter little by little to form an emulsion. Add the parsley, season with 1/2 teaspoon salt and a pinch of white pepper. Set aside and keep warm until ready to serve the fish; do not allow to boil or the sauce will separate.

Combine the flour, pimenton, 1 teaspoon salt and 1/2 teaspoon of white pepper in a baking dish. Dredge the skate and the bass fillets in the mixture. In a large saute pan over medium-high heat, add 1 1/2 tablespoons of the remaining olive oil and, when hot, add 2 pieces of skate. Cook for 4 minutes on the first side, then turn and cook an additional 2 minutes on the second side. Remove from pan to a paper towel lined plate. Repeat this process with the remaining 1 1/2 tablespoons of oil and the bass fillets.

Serve the skate and bass hot, drizzled with some of the reserved sauce and garnished with parsley sprigs.