1Preheat the oven to 200°C (400°F) Fan. Prep the potatoes. Remove both ends (the top and bottom) of the sweet potato. Peel the skin off, including the pale undercoat, until you get to the bright orange flesh. Cut the sweet potatoes into same-sized small chunks. Arrange on top of a baking tray lined with baking paper in a single layer. Give the chunks plenty of space.

2Roast in the middle of the oven for 25-30 minutes - or until the potatoes are soft and cooked through - you should be able to easily crush them with a fork. Stir the potatoes halfway through the roasting using a spatula.

3In the meantime, make the dressing. Add tahini, water and vinegar (or lemon juice) to a jar or a cup.

4Whisk together until smooth using a mini whisk or an electric mini milk frother. Set aside.

5Wash arugula really well under running water then pat dry. Alternatively, wash and dry using a salad spinner. Add to a serving plate.

6Add roasted potatoes.

7Drizzle with the dressing.

8Top with crushed walnuts and sprinkle with freshly ground black pepper.