For okra with ginger & preserved lemon, combine 500 g okra with the juice of 1 lemon in a non-metallic bowl and leave to stand for 10–15 minutes. Heat 2 tablespoons olive oil in the base of a tagine or heavy-based saucepan over a medium heat, stir in 2 finely chopped garlic cloves, 1 deseeded and finely chopped chilli and 40 g fresh root ginger, peeled and finely chopped, and cook for 3 minutes to let the flavours mingle. Drain the okra, pat dry with kitchen paper, then add to the garlic, ginger and chillies and toss to coat well. Cover and cook gently for 4 minutes until the okra is cooked through but still retains its crunch. Serve with couscous or as an accompaniment to tagines.