Lamb Roast (About)

Lamb Shank and Lamb Rack

By Cat, November 2012; updated April 2015 (Photo, right, from Wikimedia Commons) 

See also: 1. Lamb (About); 2. Lamb, Pork, Small Game Menu

I just bought a boneless leg of lamb to roast, but am unsure about how I want to flavor it, so I checked out several online recipes as well as one in Sally Fallon’s Nourishing Traditions . Wow! There are so many possibilities!

Read on for Options & Methods for lamb roast.

Options & Methods for Roast

Bone-in vs Boneless Leg of Lamb

Most of the recipes I found are for 5 – 6 pound (2 – 3 kg) bone-in leg of lamb, but boneless can also be used; however, you won’t get the healthful gelatin from a boneless cut.  A 5 – 6 pound bone-in is about 3 – 4 pounds with the bone removed.

Shoulder roast

Lamb shoulder

Lamb shoulder

(Photo, left, from Wikimedia Commons)

I’ve not roasted a lamb shoulder, but I understand that it must be roasted until it falls apart, off the bones. The first step is to score the fat with a knife in lines 1″ apart, then crossing them with more lines 1″ apart.

Bon Appetite (3) has a recipe that is fairly typical; it marinates  a 6 – 7 lb bone-in roast in a spice rub overnight in the fridge, then roasts at 325°F for 4 – 4 1/2 hours, adding just a bit of water for regular basting if the pan is dry. Food Network (4) recipe for a 2.2 lb shoulder roast rubbed with olive oil, salt and pepper, and is also roasted at 325°F  for 4 hours. For both recipes, the roasting pan/tray with the roast is tightly enclosed in aluminum foil.

A shoulder could also be braised or otherwise slow-roasted, but of course would take longer. Jamie Oliver (5) offers a recipe for a 5 lb bone-in shoulder roast, also covered tightly with foil over the roasting pan, and roasted in 325°F oven with the liquid of canned tomatoes and accompanying vegetables, for 3.5 – 4 hours

Herbs and Flavorings

A Greek tradition is lemon and oregano; the French favor with thyme. Rosemary is a wonderful herb with lamb cooked in a Mediterranean tradition. Cumin, turmeric and coriander are popular amongst middle-eastern and north-African recipes.


The type of pan varies depending on how you want to sear the roast. A instant-read meat thermometer is also useful.


This is to seal in the juices and brown the surface of the meat. If you sear on stove-top, it also provides browned bits that add flavor to the deglazing liquids. but you can also sear in the oven, which is easier if you don’t plan to make a sauce or gravy from the drippings.

  • Sear on stove-top: Use an oven-proof, heavy Dutch oven or skillet. Heat oil in skillet or Dutch oven over medium-high heat on top of stove.  Add roast; sear until brown, about 4 minutes each side. You can then remove roast and saute veggies that will cook with the roast, if desired. Place pan, with roast, in oven and roast at desired temperature.
  • Sear in oven: Use a Roasting pan, with or without a rack, or a Dutch oven. Place cut up veggies in roasting pan, to support the roast above the bottom of the pan; they can be sauteed first in olive oil or added raw. (OR place rack in roasting pan). Add roast, fatty-side up, and roast at 425° F for 15 minutes. Then reduce heat to desired temperature.
  • For slow roast, searing is not required.

Slow vs Regular Roast

The main differences between regular and slow roasting is the oven temperature, and cooking time. The lower the temperature, the longer the time. Slow roasting (as for pot roast) usually requires a little bit of moisture, which can be broth, wine or a combination of these. (200° – 300°F  is considered “slow roasting”); 325°F and abve is considered regular roasting temperature. See Slow-Roast Lamb for an example recipe.

I’ve done slow roast chicken and slow roast beef/buffalo, and have become enamored with the result. Much more juicy and flavorful than regular roasting, so would like to try that method with lamb.

A Canadian Lamb board (1) recommends never roasting above 325°F.  A recipe on (2) says,”Skip the slow-roasting, which may work for beef but simply turns lamb to mush.” Others indicate slow roasting yields a well-done pot roast, instead of rare or medium-rare.

Braise is a type of slow-roast that can be done on stove top or in the oven, and is the only way I know to cook lamb shank. See Basic Braised Lamb Shank or Leg of Lamb, Greek-Style Braised Lamb Shank or Leg of Lamb or Lamb Shank Braised with Vegetables en Papillote

Roasting Time

A 3 – 4 pound rolled and tied boneless leg of lamb will reach medium-rare in less than an hour at 325° F; a 5 – 6 pound bone-in leg will take a bit longer at the same temperature.  However, the exact time depends on many factors that differ from cut to cut:

  • oven temperature;
  • weight of the cut;
  • thickness of the cut; and
  • whether bone-in or boneless (bone-in takes longer).

Therefore it’s difficult to say how many minutes per pound to roast. It’s best to use a quick-read thermometer to gauge internal temperature for degree of doneness:

  • 125-130°F (rare)
  • 135-140°F (medium-rare)
  • 145-150°F (medium)
  • 155-160°F (well)

NOTE: internal temperature will continue to rise 5 – 10° F during standing (resting) time after roasting. See Reluctant Gourmet for more.

Standing (resting) Time

For a regular roast (not a pot roast), it  is allowed to rest at room temperature about 20 minutes after roasting. It will continue to cook (internal temperature will increase 5 – 10°F), the juices will redistribute, and the flavors will meld and improve. Carving is also easier after a rest time. And it gives you time to deglaze the pan, if desired.

However, standing (resting) is not required for a pot roast.


Stove-top searing before roasting provides rich pan juices that make wonderful sauces or gravies. The flavor of these juices can be enhanced by sauteeing veggies such as onion and carrots in the pan after searing, then setting the meat on top of the veggies to roast. Potatoes can also be added to absorb some of the meat flavorings, for an excellent side dish.

Deglazing is usually done with wine or brandy. Broth can also be added and the resulting sauce thickened with Organic cornstarch, arrowroot powder, or flour, if desired.  See also Rich Brown Gravy for more detail on making a pan sauce.


  1. Canadian Lamb board (
  2. recipe (
  3. Bon Appetit recipe (
  4. Food Network (
  5. Jamie Oliver recipe (

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