This Juicy Slow Roasted Lamb Shoulder recipe sure sounds fancy, but it is incredibly easy to make. Tender lamb dressed in a rich sun-dried tomato sauce and slow roasted in the oven. Add some creamy mashed cauliflower on the side and dig in!

Close-up shot of cooked lamb shoulder with a garlicky sundried tomato crust.

As we head toward spring, my thoughts naturally turn to one of my favorite main courses: roast lamb! It’s so lovely for a Sunday dinner, and it’s a classic choice for Easter, especially. Whatever the occasion, I’ll be cooking up a hearty bone-in lamb shoulder low and slow in the oven. For this recipe, I’m also taking a classic mint sauce and giving it a major overhaul: sun-dried tomatoes, Worcestershire sauce, soy sauce, and other goodies pack a flavor punch that works really well with the hearty flavor of lamb. So much deliciousness!

What Is Lamb Shoulder?

You might be more familiar with lamb chops and leg of lamb, but if you’re not on the shoulder bandwagon yet, you should be! Lamb shoulder is a cut that’s perfect for slow-roasting because of its rich connective tissue and higher fat content. All of that yumminess melts down as the meat slowly cooks, creating a tender, juicy result.

Overhead shot of a cooked lamb shoulder in a white roasting pan.

Ingredients You’ll Need

The ingredients for the lamb in this recipe are really simple. You’ll need a lamb shoulder, some veggies, and some seasonings. The sauce, as you’ll notice, has a bit more going on, but it’s still really easy to make – just dump it all in a blender or food processor and go!

For the Lamb

Lamb Shoulder: I usually buy a bone-in lamb shoulder, about 4 pounds in weight.
Olive Oil: For rubbing into the lamb.
Salt & Pepper
Onions: Cut up two large yellow onions into thick rings.
Garlic: Smash about six cloves of garlic with the side of your knife by laying the knife flat across the cloves and hitting it with the heel of your hand. Be careful not to cut yourself. Been there, done that. 😣
Water: A cup of water goes in the roasting pan.

For the Sauce

Worcestershire Sauce: This savory condiment works so well in all kinds of meat dishes. It’s great to keep on hand.
Apple Cider Vinegar: I often use ACV in place of white vinegar. It has a great depth of flavor, like wine, and works well for lots of dishes!
Fresh Garlic: For this recipe, I just give a rough chop to about 4 garlic cloves.
Sugar: You’ll need a tablespoon of your favorite sugar; I often use raw sugar.
Soy Sauce: A tablespoon of low-sodium soy sauce really adds dimension to the sauce.
Fresh Mint Leaves: Lamb without mint? Not in my kitchen! Or at least, not in this recipe. Mint and lamb are a classic combo, so don’t leave this out!
Fresh Parsley: You’ll need one-third of a cup of fresh parsley.
Sun-dried Tomatoes: Get the kind packed in oil.
Lemon: You’ll need the juice of two lemons for this sauce.
Hot Water: Add hot water to the sauce to get a good consistency.

How to Roast a Lamb Shoulder

To get a tender roast with a good crispy exterior, we’re going to start off roasting low and slow with a covering of aluminum foil. Then, we’ll remove the foil and finish up with high heat to brown and crisp the outside.

Raw lamb shoulder with fat cap up and slashed into a diamond pattern.

Glass bowl with blended sundried tomatoes, garlic, and mint.

Bring Meat to Room Temperature: Take the lamb shoulder out of the fridge 1 hour before you’re ready to start this recipe. Leave it in its wrappings, and place it on a large plate or tray if you think it might leak on the counter.
Prep: Preheat your oven to 450˚F. Then, combine all of the sauce ingredients in a food processor or blender and pulse until you have a chunky texture.
Prep Lamb: When the lamb has come to room temperature, put it on a large cutting board or other work surface, fatty side up. Using a sharp knife, make slashes across the top. Rub with olive oil and season liberally with salt and pepper. Finally, coat the lamb with half of the prepared sauce.
Roast Covered: In the base of a roasting pan, place your onion rings and smashed garlic cloves. Add the lamb shoulder on top, and pour a cup of water around it and over the vegetables. Then, cover with aluminum foil, place the pan in the oven, and turn the heat down to 350˚F. Roast for 3 hours.
Finish Roasting Uncovered: After the 3 hours are up, remove the aluminum foil and increase the heat to 425˚F. Check to see if there’s any liquid in the pan; if not, add a cup of water. Continue roasting the lamb for another 25 minutes, or until browned on top and the internal temperature registers at 145˚F. Start checking the internal temperature at around the 15-minute mark.
Rest & Serve: Once the lamb has cooked to an internal temperature of 145˚F, remove it from the oven. Transfer the lamb to a clean cutting board and loosely cover it with foil; let it rest for 20 minutes. Finally, drizzle it with the remaining sauce and serve.

Cooked lamb shoulder in a white roasting pan.

Tips for Success

Cooking Time. If the shoulder weighs less than 3 pounds, you can cut about twenty minutes off of the cooking time while the pan is covered with foil, so roast it covered for about 2 hours and 40 minutes instead of 3 hours. You don’t want to dry out the meat, but you still have to cook it for a similar period of time to break down the tough connective fibers in the shoulder.
Cooked Temperature for Lamb. I like to take the lamb out of the oven once it reaches the minimum safe internal temperature of 145˚F. You can leave it in a bit longer to get it to 160˚F (considered medium) or even up to 170˚F (considered well done). Use an Instant Read Meat Thermometer to check for doneness.
Grass-fed Flavor: Keep in mind that the lamb’s diet will affect its flavor. Lamb that’s been exclusively grassfed is less “sweet” than lamb fed with grain.
Slice Against the Grain: It’s very important to slice meat against the grain for maximum tenderness. Lamb shoulder is usually “filleted” off of the bone first and then sliced. For a tutorial on how to do this, check here!
Change Up the Sauce: If you are not a fan of sun-dried tomatoes, or maybe you just want something a little spicier, this recipe goes well with lots of sauce options, from chimichurri to tzatziki to pesto. Even a simple lemon-butter is great. Serve what makes you happy!

What To Serve With Lamb

If you’re not sure what to serve with slow roasted lamb shoulder, no worries; I got you. My Maple-Mustard Roasted Potatoes are an out-of-this-world side dish for roasted lamb! I recommend this amazing Roasted Butternut Squash Salad, sparkling with pomegranate seeds and full of the flavor of goat cheese, roasted squash, and crunchy walnuts. A lovely side dish of risotto made with tender sweet peas is a warm and comfy addition to the menu. Try my Sweet Pea and Crispy Bacon Risotto—it’s sure to be a favorite!

Pinching off lamb meat with stainless steel tongs.

How to Store and Reheat Leftovers

Place leftover lamb and sauce into shallow, airtight containers or food storage bags. Leftover lamb will keep for 3 to 4 days in the fridge, and up to 3 months in the freezer. Thaw it in the refrigerator overnight before reheating. To reheat, place the leftovers in a lidded, ovenproof dish and bake at 350˚F until the internal temperature of the lamb reaches at least 145˚F.

Slow Roasted Lamb Shoulder