Put the serving dish in the oven at the lowest setting to keep the vegetables warm while the meat cooks.
Slice the meat into strips ½ to 1 cm wide and about 5 cm long. Mix with the soy sauce, sherry (optional), cornstarch, sugar, and 2-3 slices of ginger. Chill for at least an hour in the refrigerator.
Preheat the oven to the lowest setting.
Prepare the vegetables. Coarsely chop the onion, thinly slice the pepper, and mince or press the garlic. Keep the snow peas whole. Cut 2-3 more slices of ginger.
Heat ½ to 1 tablespoon of oil in a frying-pan or wok. Add the garlic, onion, and bell pepper, cook 2-3 min until they start to soften, then set aside on the warmed serving plate in the oven.
Turn up the heat and add ½ to 1 tablespoon of oil. First add some salt, then immediately add the snow peas. Stir constantly for 2-3 min since they cook very quickly (the colour should stay dark green). Put the snow peas on the plate with the other vegetables. Keep the plate warm.
In the same wok, add the remaining oil and the marinated meat. Reserve the remaining marinade. Stir constantly over medium heat 5-7 min until the meat is almost cooked. Put the vegetables back into the wok, add the new slices of ginger plus the reserved marinade. Cook another 2 min. Add salt and pepper to taste. Serve.