Cooking salmon on a bed of paper-thin potato slices is both efficient and delicious: as the fish cooks it infuses the potatoes with flavour. Make sure to buy the fish in one big piece, like a roast with the skin on; pre-portioned pieces of fish will cook too quickly and be done before the potatoes are tender. All you need to make this a meal is a green vegetable. Wild-caught salmon is always preferred to farmed fish, but in a simple preparation like this it really makes a difference.
baby potatoes 570g
garlic cloves 4
extra-virgin olive oil 3 tbsp
fine sea salt
skin-on salmon fillet 680g, in 1 piece, preferably wild
fresh thyme sprigs 4
Preheat the oven to 190C/gas mark 5.
Scrub the potatoes well under cold running water, but don’t peel them. Using a mandolin or plastic V-slicer, cut the potatoes into paper-thin rounds.
If you have good knife skills, you can slice the potatoes by hand, but using a slicer is a better way to get the thin, consistent slices you want here.
Cut the unpeeled garlic in half lengthwise. Put the potato slices and garlic on a large, rimmed baking sheet. Drizzle with half of the extra-virgin olive oil, toss well with your hands, and spread out on the sheet as thinly as possible. Drizzle with the remaining oil and season with the fine sea salt.
Pat the salmon dry with kitchen towels. Run your fingers over the flesh side to detect the protruding ends of any thin white pin bones. Use your fingers or heavy tweezers to pull out and discard the bones. Season the flesh side with salt. Place the salmon skin side up on top of the potatoes. Scatter the thyme over the salmon and potatoes.
Be sure to put the fish with the skin side up – the skin will help you determine when the fish is ready.
Roast the salmon until the skin comes off easily when pulled with kitchen tongs, about 20 minutes. Start checking for doneness after about 15 minutes, but do so at the thicker end of the fish because the thinner tail end will be done first.
If the skin does not come off easily, just keep checking every few minutes until it does.
To serve, remove and discard the skin and cut the salmon into serving portions. Season with salt and serve with the potatoes.