Stir in the orzo and soy sauce, then pour in the hot stock or water. Bring to the boil, then reduce the heat and simmer for 10 mins, stirring often so the orzo doesn’t stick. In the last few minutes of cooking, stir through the cavolo nero and cook for 2-3 mins until tender. When ready, the orzo should be al dente and most of the liquid should have been absorbed.
