1. Start with the fact that chop the onion and mushrooms. By the way, instead of fresh mushrooms can be used canned mushrooms or little honey. Then cut them, by itself, is not necessary.
2. Heat the oil in a frying pan, add the chopped onion, a little passeruem it, and then add the mushrooms. If using mushrooms marinated, then this step can be skipped or fry one onion. This is the way you like - mushrooms and onions or without.
3. While the mushrooms and onions frying in oil, prepare the buns. To do this, they need to be cut in half and a little indentation inside the core.
4. Mushrooms and onions fry, stirring occasionally, until half cooked. By the time it 7-10 minutes. Oh, and do not forget to add salt and pepper to taste.
5. Then, in rolls laid thinly sliced cucumber with tomato and season with salt. Then lay on top of sauteed mushrooms and onions.
6. Sprinkle with grated cheese sandwiches, and send in a preheated 200 degree oven. For 7-10 minutes.
7. When the timer bell, measured off due time, we obtain sandwiches, passed on to the dish and decorate with chopped greens.