How to Make It
In a small saucepan, combine the vinegar with the water, sugar and 1 teaspoon of salt. Bring to a boil and simmer over moderate heat for 3 minutes.
Heat the oil in a large skillet. If necessary, cut the trout fillets into 6 pieces of equal size. Spread the flour in a pie plate and season with salt and pepper. Lightly flour the fillets, shaking off the excess. Fry the fillets in the hot oil over moderate heat until golden, about 2 minutes per side. Drain on paper towels.
Spread half the onion, carrot and bell pepper slices in a 1-quart glass or ceramic bowl or loaf pan. Set 3 fish fillets on top and cover with half the lemon slices, bay leaves and pink peppercorns. Repeat the layering with the remaining ingredients. Reheat the vinegar marinade and pour it over the fish; let cool completely. Cover with plastic wrap and refrigerate for at least 2 days and up to 1 week. Serve the trout at room temperature with the Herbed Fromage Blanc.