Fresh grey oyster mushrooms close up, Pleurotus ostreatus (illustrative photo)

Geneva-style mushroom croûte with grey oyster and chestnut mushrooms

A mushroom croûte is a golden slice of bread topped with mushrooms in cream. Our Geneva version brings together two mushrooms with different textures, the tender grey oyster and the firm, nutty chestnut mushroom, deglazes the sauce with Geneva Chasselas and finishes it under the grill with Gruyère AOP.

Serves 4 · Prep 15 min · Cook 25 min

Ingredients

  • 300 g grey oyster mushrooms
  • 200 g chestnut mushrooms
  • 4 slices of country bread, 1.5 cm thick (about 250 g)
  • 30 g butter
  • 1 tbsp neutral oil
  • 1 shallot (40 g)
  • 1 garlic clove
  • 10 cl Geneva Chasselas
  • 20 cl whole cream
  • 60 g grated Gruyère AOP
  • 10 g flat-leaf parsley
  • 1 pinch of nutmeg
  • Salt, pepper

Method

  1. Preheat the oven grill to 220 °C. Toast the bread slices for 2 minutes on each side, then rub them with the halved garlic clove.
  2. Trim the earthy base of the mushrooms. Tear the oyster mushrooms into strips by hand and separate the chestnut mushrooms into small clusters.
  3. Heat the oil and 10 g of butter in a large frying pan over high heat. Sear the chestnut mushrooms for 2 minutes, add the oyster mushrooms in a single layer and let them brown for 6 minutes, stirring little.
  4. Lower the heat, add the rest of the butter and the chopped shallot, and stir for 2 minutes. Deglaze with the Chasselas and reduce by half, about 2 minutes.
  5. Pour in the cream, add the nutmeg and simmer for 3 minutes, until the sauce coats a spoon. Season with salt and pepper and add half of the chopped parsley.
  6. Place the toast in an ovenproof dish, cover with the mushrooms and sauce, sprinkle with Gruyère and grill for 3 to 4 minutes. Serve straight away with the rest of the parsley and a lamb's lettuce salad.

Chef's tip

A runny sauce makes the bread soggy. Reduce it until it coats a spoon and toast the bread just before topping it: the croûte stays crisp underneath and melting on top. The mushrooms and sauce can be made an hour ahead and reheated just before serving.

Wine pairing

The same Geneva Chasselas as in the sauce, served chilled, or a Geneva Gamay if you prefer a light red.

Where to find these mushrooms in Geneva

Mycotopia will grow grey oyster and chestnut mushrooms in Geneva from autumn 2027, harvested to order for restaurants and home cooks. Discover our grey oyster mushrooms and our chestnut mushrooms. Are you a chef or restaurant owner? Visit our page for professionals. To hear when we open, join the waiting list at the bottom of the page.

More recipes: our grey oyster mushroom fricassee with persillade and soft-boiled egg, or all our mushroom recipes.

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