This is the wood blewit, common in late autumn and early winter along paths among leaf-litter. The cap is purplish brown and usually a bit twisted, and the gills and stem are a distinct purple. This effectively distinguishes this excellent edible fungus from any poisonous species. You can in fact buy them at some specialist shops at any time of the year, at about £25 a kilo. The cap looks different there because it dries to a buff colour.
Should you be lucky enough to find, or rich enough to buy, a kilo of wood blewits I would suggest that you make them into La Soupe Mauve. This is really just a mixture of a rich mushroom soup with what I grew up to know as barszcz, the Polish version of the universal Slavonic beetroot soup. So follow Elizabeth David’s recipe for mushroom soup à la Bressane in French Provincial Cooking. If you don’t have a copy, get one at once. The soup looks sludgy and pale brown, even made with blewits. To get the mauve effect, pour in some clear beetroot stock made from boiling an uncooked beetroot with an onion (both chopped). Once you have the colour right, serve with a blob of sour cream. Excellent.