Saturday morning and, after a regal sleep and a hearty breakfast, we're set for our foraging adventure. It's raining. A lot. But knowing that we'll be returning to the cosy Ynyshir Hall in Powys takes the edge off. We meet Xavier, a French member of the hall's staff, sporting a beret and a casual air of indifference to the weather. Samphire, sorrel and wild garlic can all be picked up around here, but it is mushrooms we are looking for. Xavier's advice is understated – "If you don't know, don't eat." He says to look around the bases of trees, but I find that I'm essentially looking for brown mushrooms at the bottom of brown trees among brown leaves. After two hours, we haven't managed to forage anything, but through the curtains of rain we do take in the breathtaking colours of the valley.

Fortunately head chef Shane Hughes and his staff weren't relying on us to return with our arms full, and the sublime nine-course tasting menu we feast on includes twice-cooked quail – poached and roasted – with quail's egg ravioli; a simple but sensational scallop dish with onion purée; and a crisp and cleansing bay leaf ice cream.

"Small and special," is how manager Joan Reen describes the establishment she's been running for 20 years, and she's spot on. The nine thoughtfully decorated rooms are themed by artist – we were in Vermeer – and have a roaring log fire. The staff are a close group and everyone does a bit of everything: the ­accountant is also the gardener; the sous chef is an ­occasional handyman; and while my partner and I were ­staying, the head chef's mum was fixing up new curtains. We were made to feel incredibly at home; it's just a shame we weren't able to contribute with a handful of mushrooms.

Stay at Ynyshir Hall, from £250 per room per night. Tasting menu, £80. The foraging walk is free but must be booked in advance.