In a large frying pan or a wok heat the oil and add ginger, chilli and garlic, cook over medium heat for 1 minute until golden and fragrant.
Add beef and cook for 5-7 minutes over high heat until the beef is sealed, add oyster sauce and soy sauce, stir to coat.
Add mushroom and snow peas and stir fry for 2-3 minutes over high heat, you might need to add a splash of water if your pan is getting too dry but bare in mind that mushrooms will also release liquid, add sesame oil and take off the heat. The snow peas should be bright green and still crunchy but cooked.
Garnish with sliced green onions and cilantro leaves before serving with rice or noodles.