Preheat the oven to 180 degrees, and butter a large oven proof pan (one with a lid if you have it).

Slice the onion into thin rings. Melt the butter in a pan, add the onions and gently cook over a low heat for 15-20 minutes until they are translucent (spoon in a little water if they are starting to catch). Add the garlic and fry for another 2 minutes until fragrant.

While the onions are gently pottering away on the stove, slice the potatoes as thinly as possible (don’t wash them as the starch will help thicken the sauce).

Spread one-third of the potato slices over the base of the buttered oven dish, then scatter half the cooked onions over the top.

Sprinkle over half the packet of smoked salmon, shredding it into small pieces as you go.

Layer the dish again in the same order; potato, onion, salmon, finally finishing with the last third of the potatoes.

Whisk the milk and cream together in a jug, season with a little salt and black pepper and pour over the dish.

Tear the slice of bread into little pieces and scatter them evenly across the potatoes.

Sprinkle the parmesan over the top and then either pop on the lid or cover with a sheet of tin foil.

Place the pan in the centre of the oven and cook for around 60 minutes; poke a knife into the potatoes after about 45 mins though just to see if they are already cooked (especially at the bottom!). When you think they are pretty much there, whip off the lid/foil and bake for a final 10 minutes to crisp up the crunchy topping. Strew over some chopped parsley or dill if you have it and serve with a crisp green salad.