Before you start, take out all the ingredients for this recipe (see picture above) and rinse any raw grains, herbs or vegetables.

STEP 1

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Preheat your oven to 240°C / 220°C fan. Take out a wide, hob- and ovenproof casserole dish.

STEP 2

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Slice the cooked beetroot and sweet potato as thinly as possible, about 2mm thick. Use a mandoline if you have one to ensure even thickness.

If you struggle to cut thin slices, you can microwave the sweet potato slices (3 minutes on high, covered) or parboil them in boiling water for 3 minutes to ensure they are cooked through when serving. Alternatively, you can extend the oven cooking time (see Step 4).

STEP 3

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In your ovenproof casserole dish, mix together the roots gratin ragu and the tin of black lentils, including the liquid from the tin. Place over medium heat and gently bring to a simmer, then turn off the heat.

STEP 4

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Lay the beetroot and sweet potato slices over the lentil ragu, slightly submerging them in the sauce, then drizzle over olive oil.

Cover the dish with a lid or a sheet of kitchen foil and bake in the oven for 20 minutes.

If the vegetables are cut into thicker slices and the microwaving or parboiling step was skipped, bake in the oven for 35 minutes instead.

Once it has cooked for the above time, remove the casserole dish from the oven and pour the miso bechamel over the top. Return it to the oven and bake for a further 10 minutes without a cover, until the sauce is golden on top.

STEP 5

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To serve, divide the gratin between dishes. Finish with a sprinkle of salt and freshly ground black pepper to taste. Enjoy!