Brush oil on both sides of fish and season with salt and pepper. Heat saute pan over medium high heat. Place the fish skin-side down and saute until golden brown, about 2 to 3 minutes. Turn over and continue cooking for 2 to 3 minutes.
Place a large spoonful of brandade onto a warmed dinner plate. Balance one Sauteed sea bass fillet on one side of the brandade. Drizzle the whole plate with the Piquillo Pepper Saffron Sauce.
Place garlic and 1/4 cup oil in a small saucepan and slowly heat over medium heat until the garlic turns a light golden brown. Place the garlic and a few tablespoons of the oil in a food processor with the salt cod and process until smooth. Pass the potatoes and parsnips through a food mill into a large bowl. Add the salt cod puree, milk and remaining olive oil and stir until combined. Stir in the butter and season with salt and pepper to taste. Keep warm.
Piquillo Pepper Saffron Sauce:
Place shallots, wine, vinegar and saffron in a medium non-reactive pot and cook until the liquid is reduced to 1 tablespoon. Slowly begin whisking in the butter until the sauce emulsifies. Season with salt and pepper, to taste, and fold in the piquillo peppers.