Preheat the oven to 220°C.
Wilt the spinach in a hot frying pan with 25g of butter.
Drain the spinach in a colander, squeeze out water, and chop finely.
Mix chopped spinach with parsley, breadcrumbs, and grated cheese in a bowl.
Fry cod fillets skin-side down in 25g of butter for 2-3 minutes until crisp.
Top fish with the spinach mixture and bake in the oven for 5-7 minutes.
Fry shallots in 50g of butter for 3 minutes, then add garlic for 2 minutes.
Add wine and stock, boil until reduced by half, then stir in cream.
Combine fennel, carrots, cucumber, onion, dill, lemon juice, and oil for the salad.
Serve cod atop the salad and drizzle with the white wine sauce.