Preheat the oven to 200°C. Wrap the diced sweet potatoes in tin foil and bake for about 10 minutes until tender. Remove the cooked sweet potato from the oven, remove the foil and leave to cool.
Place the sweet potato in a food processor with the ginger, lemon juice, vinegar, miso, sesame oil, olive oil and soy sauce then blitz until smooth. You may need to add a little water to loosen the mixture (it should be the consistency of a smooth paste).
Spread the mixture onto the Ryvita and top with sliced cucumber and carrot then sprinkle over coriander.