Melt the butter and oil in a large pan. When the butter stops foaming up, add the mushrooms, garlic, thyme, salt, and pepper and cook over medium heat for about 5 minutes. Once the mushrooms are tender, sprinkle with parsley and a touch of lemon juice. Toast the bread and arrange on a plate. If you don't like sourdough, just choose your favorite substitute- something hearty and savory. Toss the mushroom mixture and the salad greens and place on top of toast. Drizzle with a touch more oil and lemon juice. Sprinkle with shaves or grate over parmesan cheese.