Salmon with pommes anna and béarnaise

Directions

For the Pommes Anna

1. Preheat the oven to 350 F (175 C) for the Pommes Anna.

For the Salmon

1. Prepare a water bath and set the immersion circulator to 130 F (54 C) for the salmon.
2. Season the salmon fillets with salt and pepper.
3. In four vacuum pouches (or zip-top bags), divide the salmon fillets, butter, lemon, and white wine into a vacuum pouch, making sure the ingredients are evenly distributed.
4. Seal the pouches with a vacuum sealer (or with water displacement) and place them in the water bath, clipping to the side to prevent sinking. 
5. Sous-vide the pouches for 45 minutes.

For the Pommes Anna

1. Using a sharp knife or mandolin, slice the potatoes to less than 1/8-inch (~2 mm) thickness.
2. In a saucepan, melt the butter over medium heat to a light brown colour, then pour it into a bowl.
3. Use a pastry brush to grease the bottom of four shallow four-inch (12.5 cm) ovenproof cast-iron pans with some of the melted butter.
4. Cover the bottom of the pans with a neat layer of potato slices, arranging them in a tiled, overlapping, circular pattern.
5. Brush with butter and season with salt.
6. Make four more layers, repeating the layering technique, using the remaining potatoes, butter, and salt.
7. Place the pans over medium heat and cook for five minutes, without disturbing, to initiate browning on the bottom.
8. Transfer to the oven and bake for 30 minutes, until the potatoes are cooked through and the top is browned.
9. Remove from the oven and let rest for ten minutes.

For the Sauce Bearnaise

1. Combine vinegar, wine, peppercorns, reserved tarragon stems, and shallots in a small saucepan over high heat.
2. Bring to a boil and reduce the liquid until a quarter cup (60 ml) remains.
3. Strain the mixture, reserving the vinegar reduction and discarding the solids. Cool slightly.
4. Over a double boiler, add vinegar reduction and egg yolks and whisk until slightly pale and thickened enough to leave a line after running the whisk through it. Turn off heat but leave in the double boiler.
5. Add the butter slowly, a bit at a time, whisking constantly, until a thick sauce forms. Reserve a bit of the melted butter for the samphire/sea asparagus garnish.
6. Add a few drops of warm water from the bottom of the double boiler, as needed, to thin sauce to desired consistency.
7. Season with salt and stir in the chopped tarragon leaves. Keep in a warm (not hot) place.

To Plate

1. Carefully flip the (warm) Pommes Anna from the pans and transfer them to plates, presenting them neatly.
2. Remove fish from the vacuum bags gently, allowing the flavourings to stay in the bag.
3. Place the fish fillets on the plates with the Pommes Anna.
4. Add two tablespoons (30 ml) of béarnaise over the front third of the fish, allowing it to drip off and drape the fish.
5. Toss the samphire/sea asparagus with melted butter and place it near the fish as a garnish.