Peel, wash and halve the potatoes. Cook in boiling salted water for about 20 minutes. Wash the cod. Boil up salted water with peppercorns and lemon juice. Let the codfish simmer for about 15 minutes at low heat.
In the meantime, sort and wash the spinach. Collapse the spinach in boiling broth. Peel garlic, chop finely and add to spinach. Puree the spinach with the hand mixer. Then season to taste with salt and pepper.
Peel the skin off the cod. Arrange the cod sprinkled with coloured pepper and the potatoes in the spinach on a preheated plate. Garnish with lemon wedges and lemon balm.