1. Preheat the grill to high.
2. Heat a griddle pan and char the brioche buns.
3. Drizzle the mushrooms with olive oil and season well. Chargrill them until soft and cooked. Set aside.
4. In the same pan, add the red onion and a little dash of olive oil. Season well and cook until the onion is starting to caramelise. Remove to a bowl and stir in the herbs.
5. Top each bun base with a slices of beetroot, avocado, a mushroom and the herby red onion mixture.
6. Place a disc of goat’s cheese on the top, place under the grill until the cheese starts to melt and top with the other half of the bun. Serve immediately.
Recipe courtesy of The Mushroom Bureau