Cut the asparagus spears into 5 cm (2 inch) pieces. Slice the courgette and mushrooms and cut the baby sweetcorn in half lengthways. Top and tail the green beans and mangetout and cut diagonally.
Heat the stock with the sour curry paste and goji berries (if using) in a saucepan on a medium heat and bring to the boil. Add the asparagus stems, courgette and mushrooms and cook for 3–4 minutes. Add the asparagus tops, baby sweetcorn, green beans, mangetout and morning glory stems, light soy sauce, sugar and tamarind purée or lime juice and cook for another 3–4 minutes.
Add the top leaves of morning glory and cook for another minute or so, stirring gently occasionally. Taste and adjust the seasoning, using a little extra light soy sauce, sugar and tamarind purée, lime or lemon juice if necessary. Spoon into four serving bowls and serve as a side dish.