Melt the butter in a large saucepan. Add the onion and fry for 5 minutes. Stir in the warm milk, veg and potato bring to the boil, reduce the heat, cover and simmer for 5 minutes.
Add the fish,oregano, nutmeg and cook for a further 15-20 minutes until the fish and potato are tender.
Season with salt and pepper
Replacing whole milk with heavy cream increases the fat content significantly, yielding a thicker broth that coats the back of a spoon more readily. When melting the butter in a large saucepan, keep the heat at medium to prevent scorching the milk solids before the onions sweat. A heavy-bottomed Dutch oven distributes heat evenly, though a standard stainless steel pot works fine if stirred frequently to prevent sticking.
Judging Doneness by Texture
Simmering the potatoes and vegetables for five minutes before adding the fish ensures the dense starches begin softening properly. Test the potato cubes by pressing one against the side of the pan with a wooden spoon; it should yield with gentle resistance before the fish goes in. Adding the delicate haddock later prevents it from breaking apart into mush during the final fifteen to twenty minutes of cooking.
Evaluating the Fish and Potatoes
The smoked haddock is fully cooked when the flesh turns opaque and flakes apart easily under slight pressure from a fork. Simultaneously, the potato pieces must mash easily between your fingers without any hard center remaining. Incorporating the warm milk prevents the dairy from curdling when hitting the hot pan fats.