Lamb Boulangère sounds like something you’d only get at a Sunday lunch hosted by your fanciest friend, doesn’t it? But the first time I made it, I realised it’s just beautifully layered comfort food, no fluff. Honest ingredients. One pan. Big flavour.
This recipe from James Martin has that proper British charm to it. Nothing too fussy. You take lamb (shoulder or leg, whatever you can get), pile it over onions and potatoes, and roast the lot until everything smells like a French country kitchen got lost in Yorkshire. I made it last Christmas Eve with zero backup plan — bold move — and not only did no one complain, they asked for seconds. Even the cousin who “doesn’t like lamb” (every family has one).
Why You’ll Love It
- The potatoes soak up all that lamb fat — honestly, they steal the show
- It’s a full meal in one roasting tin — barely any washing up
- No gravy needed — the garlicky jus is liquid gold
- Looks impressive but secretly needs minimal prep
- Feeds a crowd with zero fuss (great for lazy hosts like me)
- Leftovers are glorious — just reheat and chuck an egg on top if you’re wild
Ingredients
- 1 joint of lamb (shoulder or leg, bone-in is best)
- 4 potatoes, thickly sliced (leave the skins on if you like — rustic vibes)
- 2 large onions, sliced
- 4 cloves garlic, peeled and sliced
- Salt and pepper, generously
- 2 sprigs fresh rosemary
- 2 tablespoons olive oil
- 100ml water
How to Make It
Build your flavour base:
Drizzle olive oil into a deep roasting tray. Layer in the onions, potatoes, and garlic — toss them around a bit so they’re all coated. Season with a good pinch of salt and black pepper. You want them happy and glistening.
Pour in your water bath:
Add 100ml water straight into the tray. It’ll help steam the potatoes and stop anything from burning while that lamb’s doing its thing on top.
Rack and lamb up:
Pop a wire rack over the veg (or rest the lamb directly on top if you don’t have one — no stress). Rub the lamb with salt, pepper, and rosemary, then place it gently on the rack.
Slow roast until the house smells ridiculous:
Roast at 170°C (about 340°F) — give it 25 minutes per pound, plus another 30 mins just to be sure. I like my lamb well-done for this one. The juices soak through the veg and make everything rich and sticky.
Check your layers:
By now the potatoes should be soft, golden, and slightly crisp on the edges. The onions? Practically melted. The water will be mostly gone, leaving a garlicky broth that’s begging to be mopped up with bread.
Let it rest, then serve:
Take the lamb out and let it rest for 15 minutes, loosely covered. Carve into thick slices and serve over the potato-onion mixture. If you’ve got any jus left in the pan, drizzle it on like you mean it.
Common Mistakes and How to Dodge Them
Why are my potatoes still hard?
They were probably sliced too thick or stacked too tightly. Spread them out in a single-ish layer so they cook evenly and soak up the juices.
Can I skip the rack?
Absolutely. Just nestle the lamb right on top of the potatoes. It’ll be even more flavourful, though a bit messier to serve.
Why is the lamb dry?
It was probably overcooked or didn’t rest properly. Stick to the timing, and always let it rest — it makes all the difference.
Do I need gravy with this?
Nope! The juices from the lamb mingle with the garlic and onion below — it’s basically built-in gravy.
Storage and Reheating
Fridge: Store cooled leftovers in an airtight container for up to 3 days.
Freezer: Slice the lamb and freeze it separately from the potatoes in freezer-safe containers. Keeps for up to 3 months.
Oven: Reheat in a foil-covered dish at 180°C (350°F) until hot — about 20 minutes.
Microwave: Works fine for single portions. Add a splash of stock or water before heating.
Frequently Asked Questions
Can I marinate the lamb first?
Totally. A quick rub with olive oil, garlic, and rosemary overnight will deepen the flavour — not essential, but lovely if you’ve got the time.
What cut of lamb works best?
Shoulder gives you that fall-apart texture, but leg is leaner and still lovely. Just don’t go too fancy — rustic is the vibe.
Can I add other veg?
Sure! Carrots, parsnips, even leeks work well. Just slice them thin so they cook through in time.
Can I make it ahead?
You can roast it a few hours earlier, then just warm the tray back in the oven, loosely covered. Great for dinner parties or lazy Sundays.
Nutrition Facts (Per Serving):
- Calories: 400
- Fat: 15g
- Carbs: 30g
- Protein: 25g
- Sodium: 500mg
- Sugar: ~2g
Try More James Martin Recipes:
James Martin Lamb Boulangere
Description
A slow-roasted lamb joint nestled over garlicky potatoes and onions, soaked in rosemary-scented juices — rustic, rich, and wildly comforting.
Ingredients
Instructions
- Layer onions, garlic, and potatoes in an oiled roasting tray. Season well.
- Add water to the tray.
- Place lamb on a rack over the veg, season with rosemary, salt, and pepper.
- Roast at 170°C for 25 mins per pound, plus 30 mins.
- Let rest before slicing.
- Serve over the soft, flavour-soaked potatoes with any juices spooned on top.
Notes
- Use bone-in lamb for better flavour and juiciness.
- If your potatoes are too wet, turn the heat up for the last 15 minutes.
- Slice your potatoes evenly so they cook at the same pace.
- Save leftovers — this is even better the next day.