Mushroom Gratin with Butter Mushrooms

Ingredients

• 1 tbsp Olive Oil
• 1 onion
• 500 g butter mushrooms
• 3 sprigs thyme
• 2 tbsp vegetable broth
• Salt
• Pepper
• 2 tbsp lemon juice
• 150 ml crème fraîche
• 1 egg yolk
• 50 g sharp cheese (e.g., alpine cheese, Greyerzer)
• 2 Tbsp whole-grain breadcrumbs
• 2 tbsp walnuts

Instructions

1. 1.

   Peel and dice the onion; clean and cut the mushrooms into bite-sized pieces. Heat a little olive oil in a pan, add the onion cubes and sauté briefly. Add the trimmed thyme and white wine vinegar, cook for about 3 minutes, season. Mix this with the mushrooms and transfer to a greased baking dish.

2. 2.

   Grate the cheese and chop the walnuts.

3. 3.

   Whisk together the crème fraîche, egg yolk, cheese, breadcrumbs, and walnuts; season with salt and pepper. Spread the mixture over the mushrooms and bake until golden brown for 15–20 minutes.