Description

This slow-cooked harissa lamb recipe features a succulent whole leg of lamb infused with a vibrant, homemade harissa paste made from dried chillies and aromatic spices. The lamb is roasted low and slow with red onions until tender and juicy, then served with a rich, spiced onion gravy that perfectly balances heat and depth of flavor.

Ingredients

Scale

Harissa Paste

20 dried chillies
6 garlic cloves, grated
1 tsp salt
100ml olive oil
2 tsp ground coriander
2 tsp ground cumin
2 tsp caraway seeds
2 tsp smoked paprika
2 tbsp red wine vinegar

Lamb and Roasting Ingredients

2kg whole leg of lamb on the bone
10 red onions, cut in half
300ml chicken stock
4 tbsp chopped coriander

Instructions

Prepare the Harissa Paste: Place the dried chillies in a heatproof bowl and cover with freshly boiled water. Cover and leave to soak until cool enough to handle. Drain, reserving the soaking water, remove stalks, and pat dry with kitchen paper. Blitz the chillies in a food processor with grated garlic, salt, olive oil, ground coriander, cumin, caraway seeds, smoked paprika, and red wine vinegar until smooth. Add reserved water if needed to loosen the purée. This paste will keep chilled for up to one month.
Prepare the Lamb: Make 15 cuts, each about 3-5 cm long, all over the leg of lamb. Reserve 1 tablespoon of the prepared harissa paste, then rub the remaining paste all over the lamb, pressing some into the cuts. Arrange the halved red onions in a large roasting tin and place the lamb on top. Leave the lamb at room temperature for 1 hour, or cover and refrigerate overnight for deeper flavor.
Roast the Lamb: Preheat the oven to 160°C (140°C fan)/Gas Mark 2. Roast the lamb for 4 to 5 hours until the meat is extremely tender and easily pulled apart with a fork.
Prepare the Onion Gravy: Remove the lamb from the tin and place it on a serving plate or board. Pour the chicken stock into the roasting tin if flameproof; if not, transfer the onions and juices to a saucepan. Bring to a boil, scraping the pan to loosen browned bits. Simmer until the liquid reduces by about one-third, forming a thick, rich onion gravy.
Finish and Serve: Stir the reserved tablespoon of harissa paste and chopped coriander into the gravy. Serve the lamb alongside the fragrant, spiced onion gravy for a hearty, flavorful meal.

Notes

Soaking the dried chillies makes them easier to blend into a smooth paste.
You can prepare the harissa paste in advance and refrigerate for up to one month.
Leaving the lamb to marinate overnight intensifies the flavors.
Low and slow roasting is key to tender, flavorful lamb.
Use a wooden spoon to gently scrape browned bits from the roasting tin for maximum gravy flavor.

Prep Time: 20 minutes plus 1 hour resting (or overnight marination)
Cook Time: 4 to 5 hours
Category: Main Course
Method: Roasting
Cuisine: North African/Middle Eastern

Keywords: slow-cooked lamb, harissa lamb, roasted leg of lamb, spicy lamb recipe, harissa paste, slow roast, North African lamb