Quick Recipe Version (TL;DR)

Yield: 6 servings
Prep Time: 45 minutes
Cook Time: 35–40 minutes
Total Time: 1 hour 35 minutes (including resting)

Quick Ingredients

1.5–2 lb (680–900 g) lamb loin, trimmed
Salt and black pepper
2 tbsp olive oil, 2 tbsp butter (divided)
1 lb (450 g) cremini or button mushrooms, very finely chopped
2 shallots, 2 garlic cloves, 1 tbsp fresh thyme leaves
2 tbsp dry white wine (or broth)
2–3 tbsp Dijon mustard
6–8 thin slices prosciutto
1 sheet puff pastry (about 14 oz / 400 g), thawed but chilled
1 egg + 1 tbsp water (egg wash)

Do This

1. Pat lamb dry, season well, and sear in hot oil until browned on all sides (about 6–8 minutes). Cool, then brush with Dijon.
2. Cook finely chopped mushrooms, shallots, garlic, thyme, butter, and wine until very dry and paste-like (duxelles). Cool completely.
3. On plastic wrap, overlap prosciutto slices, spread with duxelles, and place lamb on top. Roll tightly into a log and chill 20–30 minutes.
4. Roll out chilled puff pastry into a rectangle. Unwrap lamb and place in center, then wrap puff pastry around it, sealing edges well. Chill 15 minutes.
5. Brush with egg wash, score lightly with a knife, and sprinkle with salt.
6. Bake at 400°F (200°C) for 30–35 minutes, until pastry is deep golden and lamb reaches 125–130°F (52–54°C) for medium-rare.
7. Rest 15 minutes before slicing thick pieces and serving.

Why You’ll Love This Recipe

An impressive, restaurant-style centerpiece that is surprisingly doable in a home kitchen.
Juicy, tender lamb wrapped in a flavorful mushroom duxelles and crisp, buttery puff pastry.
Can be prepped ahead and baked just before guests arrive for stress-free entertaining.
Beautiful golden presentation that feels special for holidays, anniversaries, or dinner parties.

Grocery List

Produce: Cremini or button mushrooms, shallots, garlic, fresh thyme, fresh rosemary (for garnish, optional)
Dairy: Unsalted butter, 1 egg
Pantry: Lamb loin (center-cut), puff pastry sheet, olive oil, Dijon mustard, dry white wine (or chicken/vegetable broth), salt, black pepper, all-purpose flour (for dusting), flaky sea salt (optional)

Full Ingredients

For the Lamb

1.5–2 lb (680–900 g) lamb loin (center-cut, also called lamb backstrap), trimmed of silverskin
1.5 tsp kosher salt (or 1 tsp fine sea salt)
1 tsp freshly ground black pepper
2 tbsp olive oil
2–3 tbsp Dijon mustard

For the Mushroom Duxelles

1 lb (450 g) cremini or button mushrooms, very finely chopped (by hand or pulsed in a food processor)
2 small shallots, finely minced
2 garlic cloves, finely minced
1 tbsp fresh thyme leaves (or 1 tsp dried thyme)
2 tbsp unsalted butter
1 tbsp olive oil
2 tbsp dry white wine (or low-sodium chicken or vegetable broth)
1/2 tsp kosher salt, plus more to taste
1/4 tsp freshly ground black pepper

For Assembly & Baking

6–8 thin slices prosciutto (enough to wrap around the lamb)
1 sheet puff pastry, about 14 oz (400 g), thawed but kept cold
All-purpose flour, for dusting the work surface
1 large egg
1 tbsp water
Flaky sea salt, for finishing (optional)
Fresh thyme or rosemary sprigs, for garnish (optional)

Step-by-Step Instructions

Step 1: Prepare and Sear the Lamb

Pat the lamb loin very dry with paper towels. If there is any remaining silverskin, carefully trim it away with a sharp knife. Season the lamb all over with the 1.5 tsp kosher salt and 1 tsp black pepper, pressing the seasoning gently into the meat.

Heat 2 tbsp olive oil in a heavy skillet (cast iron works well) over medium-high heat until shimmering and just starting to smoke. Add the lamb and sear on all sides, including the ends, until deeply browned, about 6–8 minutes total. You are not cooking it through, just building a flavorful crust.

Transfer the seared lamb to a plate and let it cool to room temperature, about 15 minutes. Once cool enough to handle, brush it all over with 2–3 tbsp Dijon mustard. Set aside while you make the mushroom duxelles.

Step 2: Make the Mushroom Duxelles

In the same pan (wipe out any burned bits if needed), add 1 tbsp olive oil and 2 tbsp butter over medium heat. When the butter is melted and foamy, add the finely chopped mushrooms and 1/2 tsp kosher salt. Cook, stirring often, until the mushrooms release their moisture, it evaporates, and they start to brown, about 8–10 minutes.

Add the minced shallots, garlic, and thyme. Continue cooking, stirring frequently, until the mixture is very dry and paste-like, about 5–7 minutes more. You want as little moisture as possible so the pastry stays crisp.

Pour in the 2 tbsp white wine (or broth) to deglaze, scraping up any browned bits from the bottom of the pan. Cook until the liquid has completely evaporated. Taste and adjust salt and pepper as needed. Transfer the duxelles to a plate or shallow bowl and let it cool completely to room temperature.

Step 3: Wrap the Lamb in Prosciutto and Duxelles

Lay a large sheet of plastic wrap on your work surface. Arrange the prosciutto slices in overlapping rows on the plastic, forming a rectangle slightly longer than the lamb and wide enough to wrap around it. The pieces should overlap so there are no gaps.

Spread the cooled mushroom duxelles evenly over the prosciutto, leaving about a 1/2 inch (1 cm) border all around. Place the mustard-coated lamb at one long edge of the rectangle.

Using the plastic wrap to help you, roll the prosciutto and mushroom layer tightly around the lamb, like a sushi roll. Twist the ends of the plastic wrap to secure and firm up the shape. Chill this wrapped log in the refrigerator for 20–30 minutes. This helps the Wellington hold its shape inside the pastry.

Step 4: Prepare the Puff Pastry

While the lamb log chills, preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.

Lightly flour your work surface and place the chilled puff pastry sheet on it. If the sheet is very thick, lightly roll it out into a rectangle about 1/8 inch (3 mm) thick and large enough to fully wrap the lamb log with a small overlap and sealed ends (approximately 12 x 14 inches / 30 x 35 cm).

Beat the egg with 1 tbsp water in a small bowl to make an egg wash. Set aside.

Step 5: Encase the Lamb in Puff Pastry

Remove the lamb log from the fridge and carefully unwrap the plastic. Place the log near one long edge of the puff pastry, leaving a small border.

Brush the opposite long edge and the short ends of the pastry lightly with egg wash. Roll the pastry snugly around the lamb, overlapping the egg-washed edge so it seals. Press gently to secure the seam. Fold the short ends under the log to completely encase the lamb and seal well, pinching with your fingers if needed.

Transfer the wrapped Wellington, seam-side down, to the prepared baking sheet. Use a sharp knife to trim any excess pastry if needed. Chill the assembled Wellington in the refrigerator for 15 minutes to help it keep its shape during baking.

Step 6: Decorate, Egg Wash, and Score

After chilling, remove the Wellington from the fridge. Brush the entire surface evenly with egg wash, making sure to coat the sides and ends.

For a classic look, use the tip of a sharp knife to lightly score a crosshatch or diagonal pattern on the pastry. Cut only through the surface, not all the way through. This is decorative and also helps steam escape.

If desired, sprinkle a small pinch of flaky sea salt over the top for extra crunch and flavor.

Step 7: Bake to Golden Perfection

Bake the Lamb Wellington at 400°F (200°C) for 30–35 minutes, rotating the pan halfway through for even browning. The puff pastry should be a deep golden brown.

To check doneness, insert an instant-read thermometer into the center of the lamb (through one end to avoid piercing the pastry top). For medium-rare, aim for 125–130°F (52–54°C). The temperature will rise a few degrees as it rests.

If the pastry is browning too quickly before the lamb is done, tent loosely with foil for the last 5–10 minutes.

Step 8: Rest, Slice, and Serve

Transfer the baked Wellington to a cutting board and let it rest for at least 15 minutes. This is important; it allows the juices to redistribute and makes slicing cleaner.

Using a sharp serrated knife, slice into thick pieces, about 1–1.5 inches (2.5–4 cm) wide. Wipe the knife between cuts if needed for neat slices.

Arrange slices on a warm platter or individual plates. Garnish with fresh thyme or rosemary sprigs and a pinch of flaky salt, if using. Serve immediately, ideally with simple sides like roasted potatoes and seasonal vegetables to let the Lamb Wellington shine as the star.

Pro Tips

Dry is your friend: Cook the mushroom duxelles until very dry; excess moisture is the main reason puff pastry turns soggy on the bottom.
Chill between stages: Briefly chilling the wrapped lamb, then the assembled Wellington, helps everything hold its shape and bake more evenly.
Use a thermometer: Because the lamb is encased in pastry, an instant-read thermometer is the most reliable way to hit your perfect doneness.
Keep pastry cold: Work quickly with puff pastry and return it to the fridge if it becomes soft. Cold pastry puffs higher and bakes flakier.
Slice with confidence: Resting time plus a sharp serrated knife equals beautiful cross-sections that show off all the layers.

Variations

Herb-crusted lamb: Mix finely chopped rosemary, parsley, and a little grated Parmesan into the duxelles for an extra-herby, savory layer.
Spinach and mushroom: Stir a handful of finely chopped, well-drained sautéed spinach into the duxelles for more color and a subtle earthy flavor.
Mini individual Wellingtons: Instead of one large loin, use 4 smaller lamb loins or thick medallions and wrap each individually. Reduce baking time to about 18–22 minutes.

Storage & Make-Ahead

Make-ahead: Assemble the Wellington up through wrapping in puff pastry and scoring the top. Cover well and refrigerate for up to 12 hours before baking. For the best puff, brush with a fresh coat of egg wash just before it goes into the oven. You can also make the mushroom duxelles up to 2 days in advance and store it in an airtight container in the refrigerator.

Leftovers: Store cooled slices in an airtight container in the refrigerator for up to 2 days. Reheat gently in a 325°F (165°C) oven on a parchment-lined tray for 10–15 minutes, until warmed through. The pastry will not be as crisp as fresh, but this method keeps it from going soggy.

Freezing: For best results, freeze the unbaked assembled Wellington (without egg wash) on a tray until solid, then wrap tightly in plastic and foil. Freeze for up to 1 month. Bake from frozen at 375°F (190°C), adding 10–15 minutes to the baking time and checking the internal temperature carefully. Apply egg wash just before baking.

Nutrition (per serving)

Approximate values per serving (1/6 of recipe): about 550 calories; 36 g fat; 24 g carbohydrates; 30 g protein; 2 g fiber; 2 g sugar; 900 mg sodium. Actual values will vary based on exact ingredients and portion sizes.

Elegant Lamb Wellington with Mushroom Duxelles in Puff Pastry