Danesfield House, Marlow-on-Thames

Aiden Byrne is talking like a man possessed. Ask the 32-year-old executive chef of Danesfield House, near Marlow-on-Thames, where the concept for risotto featuring scallops, white truffles and white chocolate comes from and he answers by talking about a dish of red mullet, cacao beans and coffee.

"I hadn't done the red mullet till yesterday but it's been in my head for months," he explains. "That's what happens when I think of dishes. I taste them on my tongue before I even cook them. You are in the kitchen at every service and surrounded by smells and flavours. It's what inspires you."

So the truffle risotto comes with chocolate after Byrne decided it needed something sweet. "The Parmesan then balances them, with nasturtiums to add a bit of pepperiness. I started with sorrel, but it was too much. A little lemon juice helps to balance it, too." Byrne, obviously, is revelling in a time when ideas are arriving thick and very fast - to the extent that he has taken to noting everything down on a palm-held computer for fear of forgetting.

He may well need the help. He arrived in Buckinghamshire last July after two years as Tom Aikens's head chef in Chelsea, then the Commons restaurant in Dublin, Peacock Alley, Roscoff, Pied à Terre and Adlards. Coming from such a hard-core restaurant background, Danesfield House is a much bigger job. He has to cope with 86 bedrooms, banqueting, a second restaurant called the Orangery, not to mention breakfast. All this before he starts to get to grips with the 28-seat Oak Room, the hotel's fine-dining showcase.

However, Byrne's creativity does not seem to have been dimmed by the scale of the responsibility. Provocative combinations are balanced on the menu by more classic pairings, such as foie gras and fig, or squab pigeon with an onion tart. But every dish is confident and busy and has the capacity to surprise.

The pigeon, for example, appears with the breast stuffed with a fine dice of Alsace black lardons and confit shallots, then wrapped in ventrèche bacon. Across the dish is a long, thin piece of filo, layered with onions. By the breast is a cute little onion cake. For a final flourish, the pigeon leg is served with the claw still attached, scraped clean except for one central talon, which rises up from the plate like some witch's earring. Disconcerting, but fun.

Fennel gazpacho, meanwhile, in Byrne's hands, is not the light refresher between courses it sounds like. Instead, cucumber sorbet, two different fennel mousses, dill purée, diced apple and diced cucumber topped with a fennel crisp combine to give a heady and punchy mix.

There are copious other treats to get excited about: a perfectly round and panéd deep-fried ball of foie gras mashed potato on a stick; a stunning canapé of salt cod mousse and fennel cream, separated by a barrier of basil purée; minced scallop served in the shell with basil; foie gras rolled in gingerbread; and, from pastry chef Elwyn Boyles, a zingy combination of roast pineapple and passion fruit.

The kitchen has 18 chefs, including a stand-alone banqueting chef who has helped Byrne deal with the culture shock of that extra section. "I was trying to do stuff in banqueting that just wouldn't work," he says.

The new owners of Danesfield House are planning a major refurbishment for the end of the year, which will give Byrne a huge kitchen garden and a bigger kitchen, but will also increase the number of rooms from 86 to 120. The plan is to put Danesfield into the premier league of Britain's country house hotels. In Byrne, the hotel has now found a chef with the enthusiasm and gastronomic ambition to match.

• Terrine of foie gras with fried red fruits and fig tuile
• Langoustine and cèpe sabayon with shrimp mayonnaise and cèpe bread
• Carpaccio of tuna with chilled tomato mousse, heritage tomato salad
• Red wine-poached turbot with mushroom duxelle, scallop tartare and chervil cress
• Loin of lamb with green olives, cardamom, mussels and celery
• Oak-roast Iberico ham with pumpkin lasagne and manchego cheese
• Praline mousse with yogurt sorbet and hazelnut sponge
• Strawberry jelly and sorbet with basil panna cotta and lime parfait
• English and French farmhouse cheese

Danesfield House Hotel and Spa, Marlow-on-Thames, Buckinghamshire SL7 2EY [map]. Tel: 01628 891010. www.danesfieldhouse.co.uk