Heat the olive oil in a saucepan and gently soften the squash for 3-4 minutes.

Add the lentils and stock, bring to a simmer, and cook for 18-20 minutes until the squash and lentils are completely soft.

Allow to cool slightly, then transfer to a blender with the yoghurt and cumin.

Blend for 2-3 minutes until velvety smooth, adding a little extra warm stock if too thick.

Pass through a sieve if any lentil skins remain.

Serve warm.