Place the potatoes in a saucepan with lightly salted cold water and bring to the boil. Reduce to a simmer for around 30 minutes or until the potatoes are fully cooked

Meanwhile, heat the oil in a heavy-based pan over a medium to low heat. Add the courgette and garlic and cook until tender - stir frequently to avoid browning. Remove from the pan and set aside to cool

Trim the chicken and dice into medium-sized cubes. Place in the food processor and blend until smooth. Add the cooled courgette to the food processor and blend until smooth

Add the egg and salt, Roquefort and another blue cheese, and blend into a smooth paste. Add the cream and blend again – be careful not to over mix as the cream will split. Form into quenelles and steam for 12-15 minutes, set aside for later use

Drain the potatoes. Mash them while adding the butter, horseradish, salt and sugar. Mix well and pass through a drum sieve

Place in a saucepan to reheat and cover the surface with baking parchment to keep moist. Combine with a little hot water when reheating to serve

For the mushrooms, heat the oil in a frying pan and once hot, add the mushrooms and sauté for 1 minute before adding the garlic, thyme and rosemary

Cook for about 5 minutes more, or until tender. Set aside to keep warm

For the spinach and leeks mixture, place a heavy pan over a medium heat and add the butter. Add the leeks and cook for 5 minutes, or until tender

Add the spinach and season with a pinch of grated nutmeg and some salt. Transfer to a colander to drain and set aside in a warm place

For the carrots, cut each one into four, by first cutting in half lengthways and then across the middle. Use a peeler or paring knife to shape each piece into a barrel shape

Cook in boiling salted water for 10 minutes or until the carrots are cooked but still firm. Drain and keep warm once cooked

Preheat the oven to 180°C/gas mark 4. Heat the oil in an oven-proof frying pan until smoking. Sear the beef fillets for 1 minute on each side, or until golden brown

Place the beef in the oven for 4-5 minutes to achieve a medium rare finish - you can cook for longer if you prefer steak well done. Allow to rest for 5 minutes before serving - reserve the pan juices

To serve, place a bed of the leek and spinach mix in the middle of each plate, lay the beef fillets on top. Add the blue cheese mousse on top of the beef and a quenelle of the horseradish mash alongside

Arrange the carrots next to the mash and the mushrooms with the mousse. Garnish with a sprig of rosemary and sliced fennel. Drizzle with pan juices and serve immediately