For the fish gratin with cucumber and ginger rice, dice the shallot and sauté in hot olive oil with the rice until translucent.
Pour in the vegetable soup and simmer for 10 minutes, stirring repeatedly. Add the ginger and season to taste.
Brush a baking dish with olive oil and spread the rice on the bottom of the dish. Season fish fillets with salt and lemon juice and place on top of the rice.
Cut the cucumbers into thin slices, place them on top of the fillets like a roof tile and sprinkle with dill and salt. Set the stove to 180 °C top heat.
Heat the olive oil, brown the flour in it, pour in the milk and cook for a few minutes, stirring. Stir in the Parmesan cheese and lemon juice and season to taste with salt and pepper.
Pour the sauce over the cucumbers so that everything is well covered. Mix the breadcrumbs with the Parmesan and sprinkle on the gratin.
Bake au gratin for about 30 minutes, until the surface is brown and crispy. Serve the fish gratin with cucumber and ginger rice.