For the steak, season the steaks, to taste, with salt and freshly ground black pepper.
Heat half of the butter in a frying pan over a medium heat. When the butter is foaming, add the seasoned steaks and fry for 1-2 minutes on each side (for medium rare), or until cooked to your liking. Remove from the pan and set aside on a warm plate to rest.
Add the remaining butter to the pan the steaks were cooked in. When the butter is foaming, add the shallots and fry for 1-2 minutes, or until softened.
Add the garlic, peppercorns and thyme and cook for a further 2-3 minutes, or until softened.
Add the brandy and light with a match. Allow the flames to flare up and cool down. (CAUTION: Keep the pan well away from your face and eyes and surrounding objects).
Add the stock and cook for another few minutes until reduced by half then add the cream and return to a simmer.
Cook for another minute then season with salt and freshly ground black pepper.
For the mash, place the potatoes into a pan of salted water and bring to the boil. Reduce the heat and simmer for 12-15 minutes until the potatoes are tender.
Drain the potatoes and return them to the pan, then place the pan on the heat for one minute to steam off any excess moisture.
Mash the potatoes well, then add the butter and milk, beating to form a smooth mash. Season with salt and freshly ground black pepper.
For the beans, bring a saucepan of salted water to the boil, then add the beans and boil for 2-3 minutes until just tender. Drain and set aside.
Heat a frying pan until medium hot, add the butter and heat until foaming then add the hazelnuts and cook until lightly toasted.
Add the olive oil and sherry vinegar and whisk to combine.
Season with salt and black pepper then add the beans and parsley and toss to coat.
To serve, spoon the mash onto the plate then place the steak alongside. Place the beans next to it then spoon over the peppercorn sauce.