Preheat the oven to 180C degrees.
Cut the squash into wedges (remove these seeds) and put them in a large tray. Add the onion and garlic (no need to peel them).
Cut the carrot into 4 long pieces. Put these between the squash wedges. Scatter the thyme leaves on top, season with salt and pepper, then drizzle with some olive oil.
Bake in the oven for about 30-40 minutes until the vegetables are tender. Let them cool in the tray. Chill if you want to make the soup another day.
When the veggies are cool, remove the skin of the squash, garlic and onion and roughly chop them. Put them in a in a saucepan together with the carrot pieces and any cooking jus from the pan.
Add the drained chickpeas and the stock, then bring to the boil. Simmer for 10 minutes, then add the coriander leaves and turn off the heat. Using a stick blender, pulse the mixture until you get a smooth, silky soup.
Serve warm with a dash of lemon juice or cider vinegar and chilli flakes/ground pepper, if you like.