Preheat the oven to 220°C and boil the kettle. Peel the potatoes, sweet potatoes, and beetroot. Slice each one very thinly (a mandolin works best for even slices). 

Steep beetroot slices in boiled water for 5 minutes (to reduce the colour bleeding into the rest of the dish). Rinse & Drain.

 In a greased baking dish, stack the potato, sweet potato and beetroot slices upright and tightly packed, in order of potato first, followed by sweet potato, then beetroot. Tuck small pinches of grated cheese between slices as you go.

In a bowl or jug, whisk the IMANA White Instant Sauce sachet with the milk until smooth. Pour this mixture evenly over the arranged vegetables, allowing it to seep into the gaps.

Cover the dish tightly with foil and bake at 220°C for 40 minutes. After 40 minutes, remove the foil, reduce the heat to 200°C, and bake for a further 20 minutes, or until the vegetables are tender, the liquid has reduced  and the top is golden and crispy.

Allow to rest for 5 minutes before serving so the layers settle and the colours show beautifully when sliced.