When I was at Uni I shared with a number of other students, one of them a Tibetan guy who for the 5 years was terribly home sick. He would make all the foods he missed including homemade beer (a Tibetan tradition apparently) and then invite friends around. There is a very intricate way to seal the momos or you can go the easy path and just fold in half. The traditional way is to draw up 4 points around the circular dough and seal leaving a hole in the middle. When cooked you pour some sauce in the hole.