This smoked haddock gratin is a delicious and simple comfort food dish; the milk that is used to poach the fish is used to make a rich cheese sauce before everything is baked until golden and bubbly.
Course Main Course
Cuisine British
Keyword haddock au gratin, smoked haddock and potato gratin, smoked haddock gratin
Pour the milk into a 15cm or 6" saucepan and add the peppercorns and bay leaf.
Cut the onion in half, then peel it and trim up the root; you do not want the onion to fall apart, so do not take off too much, just enough to clean off any roots.
Place the milk pan on the stove and bring it to just below boiling point, then reduce the heat to low and allow it to simmer for 5 minutes.
Place the smoked haddock in a bowl large enough to hold it in a single layer, cut the fish if you need to, and when the milk has had its 5 minutes, pour it over the fish and let it sit for 10-15 minutes.
Bring a 20cm or 8" saucepan of water to a boil with 1 teaspoon of salt.
Cut the potatoes into 5-7mm (¼") thick rings and throw them into the pan of boiling water and parboil them for 8 minutes, then drain and set aside.
Place the spinach in a 30cm or 12" frying pan or skillet (with a lid) with a splash (2-3 tablespoons) of water over a medium heat, and add a lid, then cook until it wilts completely. Then remove and set aside.
When the fish has had 10 minutes, remove it from the milk (do not throw the milk away, we need it later), then flake the fish, discarding the skin and any bones. Place the fish in a bowl.
When the potatoes are cooked, strain them and allow them to steam dry for a minute to two, then add them to the flaked fish.
Strain the milk through a fine mesh sieve into a jug and discard the onion, pepper and bay leaf. You will only need 300ml of this (1¼ Cups).
Squeeze as much moisture as possible from the spinach and divide it between two gratin dishes. I use ones that hold around 500ml (2 cups) of liquid and measure 18cm x 12cm (7" x 4").
Divide the potato and haddock mixture between the two bowls.
Heat a 15cm or 6" saucepan over a medium heat and melt the butter. When the butter has melted, add the flour and cook for 2-3 minutes, stirring constantly.
Pour the milk into the flour and butter mix, little by little, stirring all of the time until it forms a smooth lump-free sauce. Have a taste and add salt if needed, remember we have salty cheese to add, salty potatoes and smoked haddock in play.
Divide the sauce between the two gratin dishes, then sprinkle with the grated cheddar cheese and finally the breadcrumbs.
Cook in the oven at 200°C or 400°F for 25 minutes.
If you want a little more colour on the surface of the gratin, pop it under a hot grill for 2-3 minutes.