Cod with almond potatoes and dill butter

Ingredients

• 4 cod fillets natural, each 140 grams
• 2 l water, to poach the cod
• 1 tsp salt, to poach the cod
• 1/2 lemon, halved
• 12 almond potatoes, with skin
• 2 carrots, in thin sticks
• 1/2 celeriac, in thin sticks
• 1/2 leek, in thin sticks
• 1 dl double cream
• 120 g unsalted butter
• 1/2 tsp salt
• 6 turns of a pepper grinder
• 1 bunch dill, roughly chopped