Slice the potatoes on a mandolin to a thickness of 2mm. Place these in a large bowl and pour over the clarified butter. Season to taste. Layer the potatoes in an oven-proof terrine, pressing down each layer firmly, as you go. Once all of the potatoes have been used, cover with parchment paper and
Take the breasts from the grouse and roast the carcases in the oven for approximately 30 minutes, until golden brown. Place the browned carcases in a pan and cover with water. Simmer for 2 hours, strain the stock and reduce to one quarter of the original volume. Put the breasts into vacuum bags, two in each bag, but not touching each other and place on one side.
Place the sweetcorn in a pan with the chicken stock and cook until tender, strain, but keep the liquor. Place the sweetcorn into a liquidizer with
Halve and de-seed 60 Muscat grapes, retaining 20 for a garnish. Liquidise the remainder and pass through a fine sieve. You will need
Place the grouse breasts in the waterbath at 55°C for 12 minutes, then brown in foaming butter in a frying pan and keep warm. To serve the Pommes Anna, cut around the edge of the terrine and warm the bottom until the potato drops out. Slice the potato cake into 1cm thick pieces. Fry the slices of potato terrine in the pan used for the grouse until brown on both sides. Remove the potato and keep warm. Pour
Warm the sweetcorn velouté and pour a pool into the centre of the plate. Place the potato at the top of the plate with the grouse breasts on either side. Place the grape halves over and around and use a little of the grouse stock glaze over the breasts. Finally, garnish with tips of watercress.