Toss the carrots and the cumin with a little olive oil and season. Tip into a roasting tin and spread out. Cook for about 35 minutes until soft and starting to brown at the edges. Set aside to cool.
Crush the garlic with a pinch of sea salt in a pestle and mortar. Put the chickpeas in a food processor with the garlic, tahini and carrots. Blend to a coarse puree.
Add a glug of extra virgin olive oil and some lemon juice. Check the balance until you are happy.