Cook the beetroots in a pan of boiling
water for 5-6 mins until just tender but
still with a bite; add the carrots for the
final 2 mins. Whisk together the vinegar,
mustard, olive oil, chopped mint and
sugar, and season.
Put the rice and lentils in a bowl. Add the
carrots and beetroots, then pour over the
dressing and toss to combine. Transfer
to a serving platter and sprinkle over the
hazelnuts, feta and mint leaves to serve.