Separate bitter-mustard greens and cut into 4 inch lengths.
Bring a pot of water to the boil. Add alkaline water.
Add bitter-mustard greens and cook 5 minutes. Drain.
Heat 5 tablespoons lard or oil in frying pan and stir-fry ginger slices briefly. Add crabmeat and stir-fry a few minutes.
Add seasoning ingredients and vegetable and stir-fry briefly. Add stock.
Bring to the boil and thicken with cornstarch-paste.
Mix in remaining lard or oil and dish up. Serve hot.