Preheat the oven to 180°C/gas mark 4. To make the onion glaze for the steak, wrap the onions in parchment paper and tin foil and place onto a tray. Roast in the oven for 1 hour and 30 minutes until completely soft

Remove from the paper and foil and squeeze the onions to release their juices into the tray. Remove any outer skins from the onions and add 400ml of the water to the tray. Cover with foil and return to the oven for a further 15 minutes

Meanwhile, make a light caramel with the sugar and remaining 50ml of water. Add about 450ml of the onion juice from the tray to the caramel and reduce to a thick glaze consistency

For the brine, place the caster sugar, salt, juniper berries, garlic, bay leaf and water into a pan and heat until the salt and sugar have dissolved. Leave to cool. Once cooled, place the hanger (onglet) steak into the brine and leave for 1 hour

Preheat the oven to 190°C/gas mark 6. Evenly spread the sea salt onto a tray and place the potatoes on top. Place in the oven for 45 minutes until cooked through. Discard the salt, cut each potato in half and scoop out the middle leaving empty skins

Pass the removed potato through a sieve into a pan and add 50g of the butter, crème fraiche, milk, chives and a little salt. Mix well and place into a piping bag and reserve to fill the skins, keeping warm

Melt the remaining butter and brush the inside of each shell with it. Season with salt, place back into the oven for 5-8 mins until golden and crispy. Once golden, remove from the oven, pipe in the mashed potato and serve

To make the pickling syrup for the dressing, place all ingredients into a pan bring to the boil and reduce to a syrup

To make the blue cheese sauce, add the crushed garlic to the warm pickling syrup and infuse for 5 minutes. Place the rest of the ingredients into a blender with the garlic syrup. Blitz for 2 minutes, then season with Worcestershire sauce, Tabasco and salt and pepper

To make the crispy onion rings, add a pinch of paprika to some seasoned plain flour in a shallow dish. Pour the milk into another shallow dish and dip the onion rings into the milk, drain slightly then coat with the flour. Deep fry at 140°C until golden brown, then leave to drain on kitchen paper

When nearly ready to serve, remove the steak from the brine and pat dry. Cook on a hot barbecue (or grill), turning every so often, for 3-4 minutes until the steak is charred and cooked to medium rare. Remove from the heat and leave to rest for a few minutes before brushing with the reserved onion glaze

For the salad, mix the radish, spring onions, pea shoots and red onions together in a bowl. Place the baby gem leaves on serving boards or plates, topped with a good handful of the pea shoot salad. Crumble over the blue cheese and top with the crispy onion rings and blue cheese dressing. Slice the steak and serve with the salad and filled potato skins