To make the dressing; whisk miso paste and lemon juice together and set aside
Puree avocado, wasabi and mayonnaise in a blender. Set aside.
Preheat a greased barbecue grill on high heat. Toss mushrooms in peanut oil and season with salt and pepper. Arrange mushrooms stem-side down on barbecue. Barbecue for 3 minutes . Turn mushrooms and spoon over dressing. Barbecue for 3-4 minutes, until the sauce is hot and mushrooms are tender.
Place salad greens on serving plates, top with avocado puree, mushrooms and sprinkle with beetroot and serve.
Cook up a mushroom feast and share your mushroom creations with us for a chance to win a Weber BBQ!