Gently cook in a saucepan until they are cooked through to your liking
Stir through the miso. You won't need any salt as the miso is very salty
Pile all the vegetables into an ovenproof dish
Topping
Peel the potatoes and slice into rounds. No need to peel them if the skin is sound
Put the potatoes into a covered dish and microwave for 5 minutes. Or if you have no microwave, cook them in a tiny bit of water for 5 minutes or so, until tender
Layer the cooked potatoes on top of the vegetables
Sprinkle with cheese if you are using it, or a little oil if not
Bake in the oven at 180°C fan oven/ 200°C non fan / 400°F and Gas Mark 6, for about 25 minutes until the top is golden and crispy