Breton-Style Egg Omelet with Mushrooms (here 'tortilla' means a Spanish egg omelet, not a maize flatbread)

Ingredients

• 1 dozen eggs
• butter
• mushrooms (setas)
• 1 tablespoon flour
• roast drippings (jugo de asado, pan juices from a roast)
• 1/2 glass white wine
• 1 lemon

Instructions

1. Beat a dozen eggs well and fry in butter, lifting with two forks so the omelet cooks evenly.
2. When half-cooked, remove part of the center without piercing it, forming a hollow.
3. Make a butter sauce: whisk a tablespoon of flour into a little roast drippings, then add half a glass of white wine and the juice of one lemon.
4. Simmer the mushrooms, cut into small pieces, in the sauce.
5. Lift out the cooked mushrooms with a slotted spoon and fill the omelet; fold it over itself to cover the filling.
6. Turn it to finish cooking and serve drizzled with the mushroom sauce.