The Sauce Soften the shallots and garlic in 5 g butter Add wine and reduce to syrup Add stock and reduce to syrup Add cream and bring to a simmer Whisk corn flour into simmering cream, note the sauce will go very thick Next sauté the cleaned mushrooms in 5 g butter until tender then drain onto kitchen paper Add mushrooms to sauce and simmer for 10 minutes or so until you get a rich, indulgent sauce The steaks Pre heat your griddle or heavy based frying pan until it sizzles when you add a drop of oil Season the meat just prior to cooking Don't overcrowd the cooking base, a couple of medium sized steaks or per pan Massage with a little duck or goose fat, creating a very thin layer over the meat Cook over high heat turning the steak only once after a rich, golden crust has formed, reduce heat to medium when crust has formed Cook 3 to 4 minutes each side for medium rare Finish by adding a large knob of butter when frying or on the griddle Leave to rest in a warm place at least 5 minutes before carving To serve Reheat the sauce gently Add the chopped tarragon leaves Spoon the sauce onto warmed serving plates Carve the steaks and arrange on plate neatly Serve with homemade skinny fries and grain mustard