This slow-roasted lamb breast is a simple preparation that delivers rich flavor. A savory rub of Dijon, garlic, and rosemary coats the lamb as it cooks for hours, resulting in tender, succulent meat.
While it requires a long time in the oven, the active preparation is very quick. The low-and-slow method does all the work, breaking down the tough cut into something special. A final blast of high heat ensures a crisp, golden-brown skin.
Why You’ll Love Slow-Roasted Lamb Breast
- Tender Results from a Tough Cut: Lamb breast has a lot of fat and connective tissue. Cooking it slowly at a low temperature melts the fat and tenderizes the meat.
- Flavorful Herb and Mustard Crust: The simple rub of Dijon mustard, garlic, and rosemary creates a savory crust that seasons the meat as it roasts.
- Crisp Skin Finish: Starting low and finishing high is the key to both tender meat and a crispy, browned exterior.
Slow-Roasted Lamb Breast Ingredients
- Lamb Breast: This cut is often sold bone-in and can be flat or rolled. It’s a fatty cut, which is why it benefits from slow cooking.
- Dijon Mustard: This adds a tangy flavor and helps the rub adhere to the meat. If you prefer, a whole-grain mustard also works well.
- Fresh Rosemary: Fresh herbs provide the best flavor, but you can substitute with dried. Use about 1 1/2 teaspoons of dried rosemary if you don’t have fresh.
- Kosher Salt: The larger crystals of kosher salt make it easier to season meat evenly. If using table salt, which is denser, use about half the amount.
Exact quantities are in the recipe card below.
How to Make Slow-Roasted Lamb Breast
Step 1: Prepare the Lamb
First, preheat your oven and mix the rub ingredients in a small bowl. Pat the lamb breast dry with paper towels, then season it all over with salt and pepper. Spread the mustard mixture evenly over the entire surface of the lamb.
Step 2: Slow Roast the Lamb
Place the lamb fat-side up in a roasting pan and transfer it to the preheated 250°F (120°C) oven. Cook for 3.5 hours. This long, slow roast is essential for rendering the fat and making the meat very tender.
Step 3: Crisp and Rest
Increase the oven temperature to 400°F (200°C) to brown and crisp the skin, which takes about 15-20 minutes. After roasting, let the lamb rest on a cutting board for 10 minutes before slicing to keep it juicy.
Storage Tips for Slow-Roasted Lamb Breast
Store leftover lamb in an airtight container in the refrigerator for up to 3 days. To reheat, place slices in a covered, oven-safe dish with a splash of broth at 325°F (165°C) until warmed through.
Expert Tips for Slow-Roasted Lamb Breast
- Food Safety: The USDA recommends cooking whole cuts of lamb to a minimum internal temperature of 145°F (63°C) and then allowing it to rest for at least 3 minutes.
- The rendered fat at the bottom of the pan is very flavorful. You can save it for roasting potatoes or other vegetables.
- If your lamb breast is rolled and tied, you can leave it as is for roasting. This recipe also works for unrolled, flat lamb breast.
What to Serve with Slow-Roasted Lamb Breast?
Serve the lamb with roasted potatoes and a simple green salad to balance the richness of the meat.
Slow-Roasted Lamb Breast Recipe FAQs
Why is my lamb breast still tough?
Lamb breast needs a long, slow cooking time to break down its connective tissues. If it’s tough, it likely needs more time in the oven at a low temperature. Make sure your oven is properly calibrated and give the meat the time it needs.
Can I use boneless lamb breast?
Yes, you can use a boneless lamb breast. The cooking time might be slightly shorter. Keep an eye on the internal temperature and pull it from the oven when it reaches 145°F (63°C).
What can I do with the leftover rendered fat?
The rendered lamb fat is very flavorful. You can save it for roasting vegetables. Let it cool slightly, then strain it into a clean, heatproof jar. It can be stored in the refrigerator for several weeks.
Slow-Roasted Lamb Breast
Ingredients
- 1 lamb breast bone-in (about 1.35 kg), 3-pound
- 3 tbsp Dijon mustard 45 ml
- 1 1/2 tbsp chopped fresh rosemary
- 3 cloves garlic minced
- 1 1/2 tbsp olive oil 22 ml
- 1 1/2 tsp kosher salt
- 1/2 tsp black pepper freshly ground
Instructions
- Preheat your oven to 250°F (120°C). In a small bowl, combine the Dijon mustard, chopped rosemary, minced garlic, and olive oil.
- Pat the lamb breast dry with paper towels. This helps the skin get crisp later. Season both sides generously with kosher salt and black pepper.
- Using a brush or your hands, coat the entire lamb breast with the mustard mixture.
- Place the lamb breast fat-side up in a roasting pan, ideally on a wire rack.
- Roast for 3 hours and 30 minutes. The low temperature will slowly render the fat and make the meat tender.
- Increase the oven temperature to 400°F (200°C). Continue to cook for another 15 to 20 minutes, or until the fat cap is browned and crisp. Keep a close watch to prevent it from burning.
- Remove the lamb from the oven. Use an instant-read thermometer to confirm it has reached a safe internal temperature of at least 145°F (63°C).
- Transfer the lamb to a cutting board and let it rest for 10 minutes before slicing. This allows the juices to redistribute. Slice between the ribs to serve.
