Wash champignons and green onions. Chop green onions. Peel and chop garlic. Mix sour cream, yogurt, half a garlic and half a thyme,salt and pepper to taste. Heat the vegetable oil in a frying pan, roast champignons, add green onions in the end, salt and pepper. Mix softened butter with garlic. Halve the baguette,spread with garlic butter. Grill or bake in the oven on high heat for about 5 minutes. Mix garlic sauce with champignons, gently heat, sprinkle with thyme and serve with baguette.