Heat your oven to 200°C/Fan 180°C/Gas 6. Scrub and trim the carrots, chopping off the leaves (see our carrot top tip at the end). Slice the carrots into quarters. Tip them into a roasting tin. Add 1 tsp olive oil. Season with a pinch of salt and pepper. Toss to mix. Roast the carrots for 20-25 mins till tender and lightly charred.
While the carrots roast, peel and finely chop the onion. Peel and grate or crush the garlic. Warm 1 tsp olive oil in a casserole, tagine, deep frying pan or wok. Add the onion. Season with salt and pepper. Cook and fry over a low heat for 5 mins till glossy and soft.
Stir the garlic into the onion. Measure out 1 tsp each of the cumin and turmeric. Add to the onions with a pinch of the cayenne (it's hot, so use as much or as little as you like). Cook and stir for 1 min till the pan smells spicy.
Crumble in the stock cube. Pour in 400ml boiling water and stir to dissolve.
Drain the chickpeas. Rinse them. Add them to the pan. Cover. Turn the heat up and bring to the boil. When it’s boiling, turn the heat down and simmer for 15 mins.
Crack the egg into a bowl. Beat with a fork while pouring in the yogurt to mix them together.
Take the pan off the heat. Stir in the yogurt mix 1 tbsp at a time (the residual heat will cook the egg). Add the roast carrots to the pan. Taste and adjust the seasoning.
Pick the leaves off the coriander stalks. Ladle the tagine into a couple of warm bowls. Top with the coriander leaves and a pinch more cayenne. Serve straight away.