Description
Class: Basidiomycetes
It has a firm, squat stem which has earned it the French nickname "gros pied" (big foot).

The head of the mushroom is fleshy, round, convex and 6 to 20 cm across. Unlike other varieties which have gills, it has tubes, or rather countless little openings or "pores" which are the openings of these tubes, joined side to side. Boletus mushrooms come in various colours from white to brown, including reddish-blue and yellow.

Nutritional values per 100 g
Water: 89%; Fat: 0.4 g. They contain more protein than most vegetables (2.7 g).
Rich in vitamins E, D, K and especially those of the B group, trace elements (selenium, potassium and iron), and phosphorus. Their fibre is conducive to proper intestinal function.

Buying boletus mushrooms
They should be clean, unblemished and firm, with the cap securely attached to the stem. They are best young.

Storage
Keep in a cool, dark place. Refrigerate.
Can be kept in oil.
They retain all their flavour when dried. Place them on a platter at room temperature or in a very low oven. Once dried, they can be pulverized to be used in many dishes, or else rehydrated in cooking liquid.

Cooking tips

1. Young boletus mushrooms can be eaten raw.
2. It is best to remove the tubes on the underside of the mushroom which have a tendency to become slimy. Mushrooms must not be washed. Scrape them with a knife blade or brush them off. The caps can also be wiped clean using a damp cloth. Cut off any spoiled sections as well as the earthy bottom of the stem.
3. Never soak mushrooms in water - they are like sponges and will soak up the liquid.
4. Mushrooms can be cooked in a pan with or without fat, but always on low heat to start, in order to "sweat" them. When their cooking water has evaporated, they can then be braised or sautéed.

Gourmetpedia
Corsica - There are many varieties of boletus which are grilled and then napped with a tomato and mint sauce - a specialty of Castagniccia

Hungary - sautéed in butter with minced onion, salt, pepper and paprika. Finish with cream.

Auch - cooked in white wine

Perigord - in sauces, combined with meat juices, in fricassees or omelettes

Italy - in carpaccio - very thin slices of beef or game, sliced boletus mushrooms, olive oil, French shallots, garlic, balsamic vinegar

Switzerland - with cream and veal escalopes dipped in egg, flour and fried in butter