Created by ForeverMama on August 18, 2017
Step 1: Preheat the oven to 160°C/gas mark 3/320-degreese F.
Step 2: Boil some water in a saucepan on the stove and plunge the chopped watercress in for just a minute, or until the water comes back to the boil. Drain and leave to cool.
Step 3: Meanwhile, add a splash of olive oil to a frying pan and place on the stove over a medium heat. Add the leeks and slowly cook down until they become soft and sweet
Step 4: Place the milk in a large bowl and add about 700g of the potato slices, along with the watercress. Mix together.
Step 5: Take a rectangular baking dish and very lightly oil the bottom and sides. Evenly add the slices of potato, layering up as you go through. When you are roughly halfway through, add a layer of the leeks and then continue until you have used them all up.
Step 6: Pour over any remaining milk, then with the remaining ‘clean’ potatoes, add a final layer. Press everything down and place in the oven for 50 minutes, until the top starts to crisp up.
Step 7: After that time, add the sprinkling of Gruyère and bake for a further 10 minutes, until it’s bubbled up and browned a touch.
Step 8: You can do this all in advance if you like, with the benefit of cooling down, covering with foil and pressing overnight in the fridge by placing a tray with some tins on top. This helps to compress the potato leek side kick. Just reheat for 25 minutes or so before serving.
Step 9: To make the accompanying salmon, place all of your aromatics in a wide saucepan and fill with about a litre of water. Bring gently to a simmer and leave to cook for 10 minutes. Then place in the salmon and lightly poach them for 5 to 6 minutes, until they are just done. Lift out and keep in warm in foil while you make the sauce.
Step 10: Finish by pouring the remaining cooking liquor into a saucepan through a sieve to catch the aromatics. Quickly reduce on the stove by half then add the créme fraiche and stir through. The sauce will be quite light.
Step 11: Plate up with a slice of the potato leek side kick, a fillet of salmon sat jauntily to the side, a drizzle of sauce and some pea shoots or watercress for color.