Roast Lamb Leg with Garlic & Rosemary – The Ultimate Sunday Dinner!

Why You'll Love This Recipe

• Perfectly cooked every time with that beautiful blushing pink center! 
• The garlic-rosemary rub creates an incredible flavor crust.
• The gravy is an absolute game-changer - rich, flavorful, and perfect with the lamb.
• Uses simple ingredients for extraordinary restaurant-quality results at home.

Tools You'll Need

Ingredients

For the Lamb:

• 2.75 – 3 kg / 5.5 – 6 lb lamb leg , bone-in (Note 1)
• 1 1/2 tsp cooking salt
• 1/2 tsp black pepper

For the Rub:

• 1 1/2 tbsp fresh rosemary leaves , finely chopped
• 3 garlic cloves , finely minced
• 2 tbsp olive oil

For the Base:

• 2 whole heads of garlic , halved horizontally (Note 2)
• Few sprigs rosemary (optional)

For the Gravy:

• 4 tbsp flour , plain/all purpose
• 2 1/2 cups beef broth / stock , low sodium (Note 3)

Step-by-Step Instructions

1. Prepare the lamb: Take lamb out of fridge at least 1 hour before roasting. (Note 4)
2. Preheat oven: Preheat oven to 240°C/475°F (220°C fan) with oven shelf in the middle.
3. Make the rub: Mix rosemary, garlic and olive oil in a small bowl.
4. Season the lamb: Place lamb leg in a roasting pan. Coat with the rub using your hands, then sprinkle with the salt and pepper. Place garlic and rosemary sprigs underneath the lamb, garlic cut face up.
5. Initial roast: Roast lamb leg for 20 minutes.
6. Reduce heat and continue roasting: Turn the oven down to 200°C/400°F (180°C fan) and roast for a further 1 hour or until the internal temperature reaches 53°C/127°F for medium rare (Note 5 other doneness). Check first at 45 minutes.
7. Rest the lamb: Remove lamb from oven. Transfer lamb to plate, loosely cover with foil and rest for 20 minutes to 1 hour. The internal temperature will rise to 62°C/144°F (medium rare).
8. Make the gravy: While lamb is resting, prepare the gravy using the drippings in the pan (see detailed instructions below).
9. Serve: Serve lamb with gravy, duck fat or classic crunchy roast potatoes, peas and steamed carrots tossed with butter and parsley.

Gravy Instructions:

1. Drippings in pan: Discard rosemary sprigs. You should have around 4 – 5 tbsp of fat (drippings). If less, add butter. If much more, discard a bit.
2. Add flour: Place roasting pan on stove over medium heat. When the fat starts to bubble, then add flour. Mix flour in and cook for 1 minute.
3. Stock: Pour in half the beef stock and mix to dissolve sludge in, then add remaining beef stock and mix.
4. Garlic squidging: Use a potato masher (if you're really keen like me) to mush the garlic to squeeze out the flavour (also helps flour caught in garlic to dissolve).
5. Taste: Check salt and pepper (I don't add more).
6. Thicken: Simmer for a couple of minutes, stirring, until it starts to thicken. Take it off the stove BEFORE the gravy is the thickness you want because it will keep thickening.
7. Strain: Strain into a bowl, mushing garlic to squeeze all the liquid out. Then pour into gravy jug and serve with lamb!

Pro Tips

• Meat thermometer is essential! This is the only guaranteed way to get juicy, pink lamb every time.
• Let the lamb come to room temperature before roasting for more even cooking.
• Don't skip resting the meat - this allows juices to redistribute throughout the lamb.
• Use beef stock for the gravy rather than chicken for a deeper, richer flavor and color.

Recipe Variations

• Herb Crust: Add chopped thyme or mint to the rosemary-garlic rub.
• Spicy Version: Add red pepper flakes or a pinch of chili to the rub for a kick.
• Lemon Zest: Add lemon zest to the rub for a fresh, citrusy note.
• Boneless: For boneless lamb leg, use this method but reduce cooking time slightly.

FAQs

Can I use a boneless lamb leg?
Yes! If yours is rolled and tied, you could make this recipe but the meat is not quite as juicy because it's been cut to remove the bone. If you can, unroll the lamb to do the rub then roll it back up and tie again for excellent flavour infusion! Cook time will likely be a bit shorter.

What if I don't have beef stock?
If you cannot consume beef for religious or health reasons, then chicken broth can be substituted, though beef stock gives the best flavor and color.

How do I know when the lamb is done?
Internal temperature should reach 53°C/127°F for medium rare (will rise to 62°C/144°F while resting). This is why a meat thermometer is essential!

So there you have it - the most spectacular Roast Lamb Leg with Garlic & Rosemary that will make your Sunday dinner absolutely unforgettable! 

If you try this recipe, let me know in the comments how your crispy crust turned out.