Tip the sun dried tomatoes into a heatproof bowl. Cover with boiling water and set aside to soak.
Warm a dry frying pan over a medium heat. Add 1 tsp each of the coriander and cumin seeds. Toast for 2 mins, shaking the pan occasionally, till aromatic. Tip into a mortar and grind with a pestle, or put them in a bowl and grind them with the bottom of a jam jar to roughly grind them.
Trim the very top and bottom off the leek. Halve it and rinse out any grit. Finely slice it. Peel and finely chop the carrot. Warm a large pan for 1 min, then add ½ tbsp oil and the leek and carrot. Season with a pinch of salt and pepper. Cook over a low heat, stirring once or twice, for 5 mins till soft.
While the veg sweat, peel and crush the garlic. Finely chop the parsley stalks (keep the leaves for later). Halve the lemon. Chop one lemon half into quarters (keep the other half for later). Drain and rinse the chickpeas.
Stir the crushed spices, garlic, parsley stalks and lemon quarters into the leek. Add a pinch of harissa – it’s spicy, so add as much or as little as you prefer. Add the chickpeas and bay leaf. Crumble in the stock cube.
Pour 700ml boiling water into the pan. Give it a good stir, cover and turn up the heat. Drain the sun dried tomatoes. Finely chop them and add to the pan. Bring to the boil, then turn the heat down a little and simmer for 15 mins.
While the stew simmers, tip the couscous into a bowl and cover with 100ml boiling water. Leave to soak. Once the stew has simmered for 15 mins, stir in the couscous.
Add a squeeze of lemon juice to the stew. Taste it and add more salt, pepper, lemon juice or harissa if it needs it. Ladle the stew into 2 warm bowls. Sprinkle with a little extra harissa and the parsley leaves to serve.