Introduction: Roast Leg of Lamb

About: I helped start Instructables, previously worked in biotech and academic research labs, and have a degree in biology from MIT. Currently head of Product helping young startups at Alchemist Accelerator, previous…
Roast Leg of Lamb is traditional for Easter dinner, and is a moist and delicious alternative to turkey for Christmas, Thanksgiving, and other holidays.  It looks impressive on the platter, is easier to carve, and is almost impossible to mess up! 

This recipe shows you the basic techniques, and describes the different flavors you can add to personalize your lamb, and make it the best ever.  I've even included instructions for making a quick lamb pan gravy. 

My favorite version is shown below:  rosemary and garlic-studded lamb, with brown sugar topping.

Step 1: Tools and Ingredients

1 Leg of lamb (bone-in makes a more impressive presentation, but isn't necessary)
salt
pepper
savory (optional) (I used a handful of fresh garlic - see Step 2 for other options)
fresh herbs (optional) (Don't try to substitute dried! I've used rosemary here - see Step 2 for other options)
1/4c brown sugar (optional)

oven-safe pan large enough to accommodate lamb
paring knife
carving knife
kitchen twine (if using a boneless leg)

Step 2: Prepare Garlic and Fresh Herbs

Chop the garlic into slivers, and coarsely chop the fresh herbs.  (Wash the herbs, then remove any stems, dead leaves, or critters.)

The important thing is that you're mixing two items:  a fresh herb, and a strong savory flavor.  Any of the savories listed below can be sliced and combined with the herb of your choice.  Try out something new!

Substitution ideas:

Herbs that taste good with lamb:  rosemary (what I've used here), mint, oregano, thyme, basil. Dried herbs just won't do, so avoid them.
Savory: garlic (what I've used here), hot peppers, citrus zest (use a peeler to get large curls), dried fruit (cranberries, cherries, apricots, etc).

Step 3: Cut & Stuff Lamb

- Place leg of lamb in roasting pan.
- Cut deep slits all over the surface of the lamb, using your paring knife.
- Stuff bits of your savory and herb mixture into each slit. (See Step 2 for options.) Make sure to stuff them mostly below the surface of the meat to avoid burning your seasonings.

If you're using a boneless leg, stuff plenty of seasonings inside where the bone used to be, then tie a couple of loops of kitchen twine around the leg to hold it together nicely.  This isn't rocket science - just hold it together.

Step 4: Season Surface

Sprinkle the leg of lamb with salt and pepper, then add any other seasonings you desire.

Here I've used about 1/4 cup of brown sugar, spreading it over the top surface of the lamb in a thin layer.  If you're using sugar, don't leave spilled sugar on the bottom of the pan - it can easily burn.

You can also add chili powder, honey, a spice rub, or any other flavoring you're excited about.

Step 5: Roast Lamb

Throw the lamb in a pre-heated 400F oven.

After 15-20 minutes, turn the temperature down to 325F and continue roasting until an instant-read thermometer reads your target temperature.  This is the only way to be sure your roast is done properly!  Take temperature readings at the thickest part of the leg, but don't get too close to the bone - it will be much hotter than the surrounding meat.

Basting the leg with the pan drippings is always a good thing, and you can add more brown sugar or other seasoning if you like.

Notes on time & temperature:

Obviously the cook time will vary depending on both the size of your lamb leg and the target temperature - mine reached medium in about an hour.  I would actually have preferred medium-rare, but the temperature climbs fast near the end of cooking!  Beware, and check frequently when you're nearing target temperature.

Rare:  120-125F (center bright red, pink outer)
Medium-rare: 130-135F (center pink, light brown outer)
Medium: 140-145F  (center light pink, brown outer)
Medium-well: 150-155F (light brown center, brown outer)
Well done: 160F + (all brown, aka dry and burnt)

Step 6: Rest Meat

Place your cooked lamb leg on a platter, and let it rest for 15-30 minutes before cutting into it.  This will allow the juices to re-flow into the meat, making it properly moist, juicy, and flavorful.

Step 7: Prep Gravy

While the meat rests, pour the delicious pan juices into a pot to make gravy.

A truly excellent gravy starts with a roux, but you can make a very good, solid gravy without the added time and effort.  Here's the trick.

- Heat the pan drippings in a wide pot. 
- Sprinkle in about a teaspoon of super-fine* flour, stirring with a whisk to incorporate quickly. 
- As mixture thickens, stir in an almost equal volume of milk or half-and-half.  If you prefer less milky gravy, add incrementally and taste-test as you go; I like this ratio as lamb pan drippings are pretty strongly flavored.  (I had about 1 cup pan drippings, so used about a cup of whole milk.)
- Simmer lightly for a few minutes.  You want the flour to fully re-hydrate to thicken the mixture, but don't want to boil the milk.
- Stir, taste, and adjust seasonings.  (I had to add a pinch of salt.)  It should taste strongly of lamb, be enriched by the addition of milk, and feel soft and velvety on your tongue. 

Congratulations, you've made a quick pan gravy!


*Wondra, or "instant" flour.  It's finely-ground, low-protein flour that has been pregelatinized (steamed then dried), all making it easier to dissolve in liquid and less likely to form lumps.

Step 8: Carve and Serve

Arrange the leg of lamb on a nice oblong tray.  I like to decorate the tray with more of whatever fresh herb I've used in the lamb - in this case, rosemary.  Pour off any additional juices that may have collected, and stir them into the gravy.

Grab a fork and a carving knife, and carve the lamb at the table.  It's dead easy, and much simpler than carving a turkey - all you have to do is start on one side and cut slices until you reach the obvious bone.  Then spin the leg 90 degrees, and continue cutting.  If you're using a boneless leg of lamb, the process is even easier!  Remove any kitchen twine, and cut into 1/8-1/4 inch slices.

Save the bone for stock, and the leftover meat (if there is any!) for sandwiches.