Slice the butternut squash in half, then trim and discard the ends and spoon out the seeds (see Tip). Cut the butternut squash into 1cm-thick pieces and transfer to a large baking tray along with 2 tablespoons of olive oil, ½ teaspoon of salt and ½ teaspoon of pepper.
Finely chop the sage leaves (you’ll need about 2 tablespoons) and sprinkle over the squash pieces. Combine everything with your hands, then
Remove the baking tray from the oven. Drain and rinse the lentils, then add to the squash and mix lightly. Return to the oven and
Meanwhile, prepare the dressing by combining the mustard in a small bowl with
Remove the squash and lentil mixture from the oven and divide between 2 serving plates. Top each serving with