Spread the well-picked trout fillets in a greased casserole dish. Finely chop the onion and place over it, halved cherry tomatoes and capers form the next layer. Season the whole thing to taste with salt, pepper and herbs of Provence. Cut the jacket potatoes into thin slices (approx. 3 - 4 mm) and cover the casserole with them.
Mix the cream and ketchup, season with paprika powder and salt. Spread evenly over the casserole as a sauce.
Bake in the oven at 180 ° C for 20-30 minutes. A green salad goes well with it, e.g., arugula, or zucchini vegetables.