Flake mackerel into a food processor, ensuring there are no bones. Add lemon zest and juice, yogurt and horseradish cream and blend until smooth. Add more yogurt until the desired consistency is reached.
Season to taste and add the parsley.
Transfer to glass pots, top with a little melted butter and chill in the fridge.
Toast bread and spread pâté on top. Serve with a rocket salad.
*All information included in this recipe has been provided by Onken.