Heat the oven to 180 C / 350 F and line a tray with baking parchment.
Finely slice the onion and place in a bowl with the zest and juice of the lime, the sugar, and a good pinch of salt and pepper. Mix well to coat the onion and reserve.
Cut the squash into fine slices and arrange in a single layer on the oven tray, season with salt and pepper and spray with a little extra virgin olive oil. Bake in the oven for 15-20 mins or until starting to brown.
Meanwhile, combine the flaxseed oil with the onion mixture to make a dressing. Roughly chop the coriander. Combine the lentils, dressing and coriander in a large bowl.
Core and slice the apple into quarters and then into thin slices.
Once the squash slices are cooked, divide the lentil mixture between 4 plates, and arrange the squash and apple slices on top. Sprinkle with chilli flakes if you like.
Notes
If you are cooking your own lentils, start with 100 g raw lentils and cook according to the pack instructions. Drain and reserve.