Perfect Roast Leg of Lamb With Times and Temperatures Guide
This roast leg of lamb is a straightforward way to make a holiday or Sunday dinner feel a little more special while still keeping it simple. I use a bone-in leg of lamb, a simple garlic and herb coating, and a thermometer so the roast comes out evenly cooked and easy to serve.
If you have not made lamb at home before, this is a good place to start. The steps are simple, the timing is manageable, and the temperature guide removes much of the guesswork. Following these steps makes this one of my foolproof meat recipes.
| Prep | Cook | Rest | Total | Servings |
|---|---|---|---|---|
| 30 minutes | 1 hour 20 minutes | 15 minutes | 2 hours 5 minutes | 8 |
Table of Contents
With just a few key ingredients and some easy-to-follow steps, you’ll have a succulent and juicy lamb leg that’s perfect for your dinner party or holiday celebration. To roast a leg of lamb is easier than you may think.
Quick Facts
- What it is: This is a bone-in roast leg of lamb cooked in the oven with garlic, herbs, olive oil, and Dijon. It is a classic roast that works well for Easter, Christmas, or a Sunday dinner.
- Why you’ll love it: The method is simple, the seasoning is familiar, and a thermometer makes the roast much easier to manage. You get a browned outside, tender slices, and a roast that feels special without turning into an all-day project.
- How to make it: Let the lamb sit out for about 30 minutes, coat it with the herb mixture, and roast it at 325°F until it reaches your target temperature. Rest it before slicing so the juices stay in the meat instead of on the cutting board.
Pair the roast lamb with roasted potatoes, roasted asparagus, or sauteed green beans and you have an easy, fabulous crowd-pleasing dinner. So, let’s dive into why this roasted leg of lamb recipe is a great choice for any holiday celebration.
🥘 Ingredients for Leg of Lamb
- Bone-in leg of lamb is my choice for this dish because the bone adds flavor. Additionally the bone-in leg give the presentation that wow factor. Instead of a whole leg of lamb, a half leg of lamb is a great choice because the lamb shank is removed. The lamb shank is better when braised.
- Fresh garlic cloves are the perfect pairing for lamb. They add a pungent, savory flavor to the lamb and complement the other herbs.
- Dijon mustard adds a tangy, slightly spicy flavor to the lamb, and also helps to form a nice crust on the exterior of the meat during roasting.
- Fresh rosemary is a fragrant herb that adds a distinctive, piney flavor to the lamb. It also pairs well with garlic, making it a popular herb in many lamb recipes.
- Fresh thyme has a subtle, earthy flavor that adds a nice aroma to the lamb as it cooks.
- Olive oil helps to brown and crisp the exterior of the lamb during roasting, and also helps to keep the meat moist.
- Kosher salt and freshly ground black pepper.
- Lemon juice adds the final citrus notes to the lamb complementing the savory flavors.
Bone-In Vs Boneless Leg Of Lamb
- Bone-in leg of lamb: More traditional, a little more dramatic on the table, and often a little richer in flavor. It can be a little less even in shape, so carving takes more attention.
- Boneless leg of lamb: Easier to carve, easier to season evenly, and easier to portion. It is a good choice if you want cleaner slices and a roast that is easier to manage.
🧂Ingredient Notes And Substitutions
Most of the ingredients here are flexible, and that helps if you are working with what you already have on hand.
- You can use boneless leg of lamb instead of bone-in, but the cook time may change a little because the shape is more compact.
- If you do not have fresh rosemary, dried rosemary can work. Just use less since dried herbs are stronger.
- Dijon gives the seasoning mixture a little sharpness and helps it spread over the roast, but a coarse grain mustard will also work.
- Fresh garlic is best. Garlic powder will season the roast, but it will not give you quite the same flavor.
🔪 How To Roast a Leg of Lamb
- Pull the lamb out of the refrigerator and let stand for about 30 minutes or until it reaches room temperature. Trim any excess fat.
- Meanwhile, preheat the oven to 425 degrees F. The best way to give our lamb a nice outer sear is starting it at higher temperatures.
- Mince the garlic and in a small bowl blend with the Dijon mustard, rosemary leaves, and thyme leaves into a coarse paste.
- Using a sharp knife, make small slits into the top of the leg. Rub the garlic mixture into the slits on the leg and all over the leg.
- Place the lamb fat side up, on a wire rack in a shallow roasting pan. Roast 15 minutes. Then lower temperature to 325°F and roast about 20 minutes per pound.
- Check the cooking time and temperature in the following chart for your desired doneness. Then remove from the oven and let rest, tented with foil for 15 minutes.
- Carve lamb, against the grain, into ½-inch-thick slices and arrange on a heated platter. Decorate with remaining rosemary sprigs.
Optional Gravy
If you want to make a gravy, you can do so from the pan drippings. Following the steps in this gravy recipe will aid you in making a delicious gravy to drizzle over the lamb or on mashed potatoes.
💭 Cook’s Tips
- Always use an instant read thermometer to check the internal temperature of the meat, as this is the most reliable way to ensure that your lamb is cooked to your desired level of doneness.
- Insert a meat thermometer into the roasting lamb 30 minutes before you think the lamb is going to be done. This will help to not overcook the lamb.
- Remove the lamb from the oven 5 to 10 degrees before the desired internal temperature is reached.
- Carve the lamb against the grain.
Roast Leg Of Lamb Time And Temperature Guide
The best internal temperature depends on how you like your lamb cooked, but medium-rare to medium is where most people land. That gives you slices that are still tender and juicy without feeling too rare for the table.
A thermometer is the best way to cook a leg of lamb to the ideal temperature. Time gives you a starting point, but the internal temperature tells you when the roast is ready to come out.
| Doneness | Pull Temperature | Temperature After Rest | Estimated Time |
|---|---|---|---|
| Medium-rare | 130°F to 135°F | 135°F to 140°F | About 20 minutes per pound |
| Medium | 140°F to 145°F | 145°F to 150°F | About 25 minutes per pound |
| Medium-well | 150°F to 155°F | 155°F to 160°F | About 30 minutes per pound |
It’s important to note that the recommended time may vary depending on the size and shape of your lamb leg, as well as the accuracy of your oven temperature. So start checking your roast early instead of waiting until the end.
How To Store Leg of Lamb
If you have leftover lamb, there are a few ways you can store it to keep it fresh and delicious for longer:
- Refrigerate: You can store leftover lamb in an airtight container in the refrigerator for up to 4 days. Make sure to separate the meat from any sauces or gravies to prevent them from becoming soggy.
- Freeze: You can also freeze leftover lamb for up to 3 months. Wrap the lamb tightly in plastic wrap or aluminum foil, and then place it in a freezer-safe container or resealable plastic bag. Label the container or bag with the date and contents before freezing.
- Meal prep: If you plan on using the leftover lamb in a recipe later in the week, you can pre-chop or shred it and store it in an airtight container in the refrigerator for up to 3 days.
How To Use Leftover Lamb
Leftover roast leg of lamb has a variety of ways to serve it.
- Slice it thin for sandwiches, tuck it into wraps, or add it to grain bowls.
- Add thin slices to pita bread and top with red onions and tzatziki for Gyros.
- Warm it with roasted vegetables for another lamb dinner.
FAQs
What temperature should roast leg of lamb be cooked to?
That depends on how done you want it, but a thermometer is the best way to judge it. For a roast that stays tender and juicy, medium-rare (135°F) to medium ( 145°F) is usually the sweet spot.
How long does it take to cook a leg of lamb?
That depends on the size of the roast and how done you want it. A leg of lamb usually takes about 20 to 30 minutes per pound at 325°F, but I would always trust the meat thermometer over the time.
Should I cover leg of lamb while roasting?
No, not at the start. Roast it uncovered so the outside can brown well. If it starts getting darker than you want near the end, you can loosely tent it with foil.
How long should roast leg of lamb rest before slicing?
Let it rest for about 15 to 20 minutes before slicing. That gives the juices time to settle back into the meat, which makes a real difference once you start carving.
How do you keep leg of lamb from drying out?
The main thing is not to overcook it. Use a meat thermometer, remove it from the oven at the right time, and let it rest before slicing. That does more for a good roast than anything fancy.
Perfect Roasted Leg of Lamb
Ingredients
- 1 bone-in leg of lamb 5 to 7 pounds
- 6 garlic cloves, peeled and smashed
- 3 tablespoons Dijon mustard
- 9 rosemary sprigs (2 heaping tablespoons leaves from 6 sprigs) plus extra sprigs and branches for garnish
- 1 tablespoon fresh thyme leaves about 10 springs or 1/4 of a bunch
- 2 tablespoons virgin olive oil
- Kosher salt
- Freshly ground black pepper
- 1 lemon cut in half
Instructions
- Preheat oven to 425 degrees Fahrenheit.
- Using a sharp knife, make about 10 to 12 cuts into the fat cap on the top of the leg. Make the cuts deep, but without cutting into the meat.
- Using a mortar and pestle, blend the smashed garlic cloves, 2 tablespoons Dijon mustard, 2 heaping tablespoons of rosemary leaves, and the thyme leaves into a coarse paste. Using your fingers, press paste deeply into the cuts on the lamb leg.
- Combine the remaining mustard and olive oil. Smear this mixture all over the surface of the roast. Season lightly with kosher salt and black pepper. Place the lamb, fat side up, on a rack in a roasting pan. Squeeze the juice from the lemon halves over the lamb.
- Roast 15 minutes. Then, reduce the temperature to 325°F. Roast for about 60 to 90 minutes, about 15 minutes per pound, or until the internal temperature of the meat reaches 130 to 135°F, for medium-rare lamb (for other doneness levels, the cooking times are in the post).
- Remove the lamb from the oven. Tent the roast with foil and let the roast rest for 15 to 20 minutes in a warm place. The internal temperature will rise to about 140 to 145 degrees.
- Carve lamb into 1/2-inch-thick slices and arrange on a heated platter. Decorate with remaining rosemary sprigs.
