Set the oven to 180 C / 350 F
Cut the sweet potatoes 2 cm or 3/4 inch thick
Toss the potatoes in a little oil and sprinkle with a bit of salt. Put them in a single layer if possible in a baking casserole or tray . Bake sweet potatoes for 30 minutes till just soft.
Mix the lemon, soy, honey, ginger, garlic, coconut, stock and cornflour and whisk together. When combined add the sliced lime leaves and pour over the potatoes in the baking dish
Put the fish on top of the sauce and potatoes and sprinkle with the sesame seeds. Bake for 20 minutes (180 C). Use a timer so the fish doesn't over cook. 15 minutes for fan a forced oven
Serve with chopped chilli, sliced green onions and coriander