Add the butter into a heavy bottomed pot. Add the chopped leeks and garlic and gently sweat down until soft and jammy. Add the potatoes and cook for a further 5-6 minutes.
Meanwhile, poach the haddock on a low heat for 5-6 minutes in the milk and cream with the bay leaf and a few sprigs of thyme and tarragon. Once cooked remove the haddock from the infused milk mixture into a bowl and lightly flake.
Combine all the ingredients (except the haddock) into the pot and simmer away for 15 minutes. Add the haddock last and equally portion into bowls.
