Mix julienned cucumber with sea salt in a bowl.
Spread cucumber on a tray and freeze for 2 hours until solid, then rinse.
Preheat the oven to 190°C.
Melt 20g of butter with salt, white pepper, and lemon juice in a saucepan.
Brush turbot and scallops with the butter mixture and refrigerate.
Fry shallots in 20g of butter with water for 3 minutes, then add sliced mushrooms.
Pour in white wine, bring to a boil, and reduce for 15 seconds.
Place turbot fillets on the mushrooms, add reserved trimmings to the liquid, cover, and bake for 8 minutes.
Add scallops on top of turbot and bake covered for 3 more minutes.
Strain the liquid into a clean saucepan and let the fish rest covered for 5 minutes.
Sauté the rinsed cucumber in 20g of foaming butter until wilted.
Heat the strained liquid and whisk in 40g of butter to make the sauce.
Stir in girolles, wakame, cucumber, tomatoes, herbs, and lemon juice; heat for 2 minutes.
Serve fish and scallops on spinach, garnished with the sauce, vegetables, and extra herbs.