Heat your oven to 180°C/Fan 160°C/Gas 4. Tip the lamb into a bowl. Add 1 tsp of the ras el hanut and some salt and pepper. Toss to coat the lamb in the spice. Put to one side to marinate for 10 mins.
Tip the couscous into a heatproof bowl. Roughly chop the dried apricots. Add them to the couscous. Stir 250ml boiling water into the couscous. Pop a saucer on top of the bowl. Put to one side to soak.
Tip the tomatoes into a roasting tin. Drizzle with 2 tsp olive oil. Season. Roast for 25 mins till charred and tender. Peel and roughly chop the onion. Trim and peel the carrots. Halve and roughly chop them. Peel and grate or crush the garlic.
Warm 2 tsp olive oil in a wide pan over a medium-high heat. Add the lamb. Fry for 5 mins till golden brown all over. Turn every so often. Lift out of the pan. Pop on a plate.
Add the onion and carrots to the pan. Keep the heat lowish. Cook and stir the veg for 5 mins till they look soft and glossy. Stir in the garlic. Cook and stir for 1 min.
Crumble the stock cube into a measuring jug. Stir in 400ml boiling water to make a hot stock. Add the lamb back into the pan with any juices from the plate. Stir in the stock.
Pop a lid on the pan. Bring the tagine to the boil. Turn the heat down and simmer for 40 mins till the lamb is tender and cooked through. Stir the roast tomatoes into the tagine. Taste and add more salt, pepper and ras el hanut if you think it needs it.
Roughly chop most of the parsley leaves. Fluff up the couscous with a fork. Stir in the chopped parsley. Serve the tagine with the couscous, garnished with the last of the parsley leaves.