Preheat oven to 200c/180c Fan/Gas 6
Placed sliced carrots and onion into a bowl. Spritz with a good helping of cooking spray and add the cumin. Using your hands coat the carrots in the spice and oil.
Place onto a baking tray and into the oven for 30 - 45 minutes or until they are caramelized on the edges and you can push a fork throught them.
Once cooked, spritz a pan with cooking spray over a medium heat. Add the carrots, onion, garlic and salt. Sauté for a few minutes.
Pour in the vegetable stock and lemon juice. Cover with a lid and allow to simmer for 20 minutes.
Remove from the heat, allow to cool for a few minutes. Place into a food processor or use a hand blender. Blend until smooth.
Place back over the heat, add a twist/pinch of Black pepper and stir for a minute whilst reheating before serving.