Lamb · Slow cooker adaptation

Jamie Oliver Shepherd's Pie (Slow Cooker Adaptation)

Lean lamb, rendered until it caramelises, then bulked out with cannellini beans and mushrooms: this shepherd's pie strips back the fuss without sacrificing depth. Jamie sneaks swede into the mash and finishes the filling with a cheeky spoonful of mint sauce for that classic lamb twang.

R By Richard · Adapted from YouTube · Published 28 May 2026
⏱Prep 30 min
🍲Slow cook 6 hr (Low) / 3 hr (High)
🍽Serves 6
shepherds pie Jamie Oliver

Source video by YouTube on YouTube. This recipe was adapted with strict source-fidelity rules and is marked for human review.

This is Jamie Oliver's healthier take on the classic shepherd's pie, bulked out with cannellini beans, carrots, celery and mushrooms for extra fibre and nutrients. The lamb ragu is finished with mint sauce and Worcestershire sauce for a flavour twang, then topped with a 50/50 swede and potato mash lifted with a little cheddar. We've adapted the original hob-and-oven method for the slow cooker, building the ragu low and slow before finishing the mash topping under the grill for that crispy golden finish.

Slow cooker notes: Original is a hob ragu then oven bake. Adapted by browning the lamb and softening the onions in a frying pan first (slow cookers do not brown), then transferring to the slow cooker with the veg, beans, flour and stock to cook low and slow. Stock reduced from 800 ml to around 600 ml because slow cookers retain liquid. Mint sauce and Worcestershire sauce stirred in at the end as in the original. Mash topping made separately and either spooned over with peas and finished under a hot grill for a crispy top, or assembled in an ovenproof dish and baked at 180C for 25-30 min to crisp the top.

Editor's note: Lamb mince quantity not stated in transcript. Mint sauce given as '2 or 3 teaspoons', used 2.5 tsp midpoint. Salt quantity not stated (a little salt). Olive oil quantity for finishing rosemary not stated. Recipe adapted from oven bake to slow cooker, so timings are an adaptation rather than from source. Jamie said the pie 'will serve 600 people' which is clearly a slip for 6. | Second-pass critique flagged 3 fabricated and 2 quantified issues. See critique.issues for detail.

Ingredients

Ragu
  • lean lamb mince
  • 2 generous pinchesblack pepper
  • salt
  • 2 sprigsfresh rosemary, finely chopped
  • 2 wholeonions, finely chopped
  • 1 tincannellini beans, drained
  • 2 wholecarrots, diced
  • 2 wholecelery sticks, diced
  • 250 gmushrooms
  • 1 heaped tbspplain flour
  • 600 mlchicken or vegetable stock
  • 2.5 tspmint sauce (add late)
  • 1 tbspWorcestershire sauce (add late)
Topping
  • swede, peeled and chopped
  • 800 gpotatoes, quartered
  • 2 tbspsemi-skimmed milk (add late)
  • 15 ggood quality cheddar, grated (add late)
  • 350 gfrozen peas (add late)
  • rosemary sprigs (add late)
  • olive oil (add late)

Method

  1. Place the lean lamb mince into a dry frying pan over a high heat. Break it up and let the fat render out, browning the meat for good caramelisation and flavour.

    ~5 min

  2. Season the lamb with two generous pinches of black pepper and a little salt. Add the finely chopped rosemary and the chopped onions, and continue to fry.

    ~3 min

  3. Add the drained cannellini beans, diced carrots, diced celery and the mushrooms. Stir and fry on high heat for around 10 minutes, letting everything sink down and take on colour.

    ~10 min

  4. Stir in the heaped tablespoon of plain flour, then tip everything into the slow cooker. Pour over 600 ml of chicken or vegetable stock and stir well.

    ~3 min

  5. Cover and cook on Low for 6 hours or High for 3 hours, until the ragu is thick and rich.

    ~360 min

  6. About 30 minutes before serving, peel and chop the swede and boil for 10 to 15 minutes. Add the quartered potatoes and boil for a further 10 to 15 minutes until both are tender.

    ~25 min

  7. Drain the swede and potatoes and mash together. Add the 2 tablespoons of semi-skimmed milk and grate in the 15 g of cheddar. Season and mix to a smooth mash.

    ~5 min

  8. Stir the mint sauce and Worcestershire sauce through the ragu in the slow cooker, then transfer to an ovenproof serving dish.

    ~2 min

  9. Scatter the frozen peas in an even layer over the ragu (this stops the mash sinking), then spoon the mash over the peas. Score the top with a fork so it catches and crisps.

    ~5 min

  10. Bake at 180C / 350F for 25 to 30 minutes, or place under a hot grill for 8 to 10 minutes, until the topping is golden and bubbling. Scatter a few rosemary sprigs and a drizzle of olive oil over the top for the last 5 minutes.

    ~30 min

Frequently asked

Why do I have to brown the lamb in a pan first?
Slow cookers steam rather than brown, so all the deep, savoury caramelisation flavour in a shepherd's pie has to be built in the frying pan before the meat goes into the pot. Skipping this step gives a pale, washed-out ragu.
Can I make this vegetarian?
Yes. Jamie suggests in the video that you can leave the lamb mince out and replace it with extra mushrooms for a vegetarian or vegan version, and you will still get a comforting result. Use vegetable stock and skip the Worcestershire sauce (or use a vegan version).
Why add the mint sauce and Worcestershire sauce at the end?
Both bring a fresh, tangy lift that gets cooked away if added too early. Stirring them in at the end keeps that bright twang against the rich lamb.
Why peas under the mash?
The layer of frozen peas creates a barrier that stops the mash sinking into the ragu, so you get a clear crispy top and a clean layer of ragu underneath.
Can I assemble this ahead?
Yes. Cook the ragu in the slow cooker and make the mash on the day, or assemble the whole pie in an ovenproof dish, cool, refrigerate, and then bake from cold for around 40 to 45 minutes at 180C until piping hot and crisp on top.
Extraction notes (transparency): Lamb mince quantity not stated in transcript. Mint sauce given as '2 or 3 teaspoons', used 2.5 tsp midpoint. Salt quantity not stated (a little salt). Olive oil quantity for finishing rosemary not stated. Recipe adapted from oven bake to slow cooker, so timings are an adaptation rather than from source. Jamie said the pie 'will serve 600 people' which is clearly a slip for 6. | Second-pass critique flagged 3 fabricated and 2 quantified issues. See critique.issues for detail.