I love how this recipe combines minimal prep with maximum flavor. The garlic cloves tucked into the roast bring deep, savory notes, while rosemary and black pepper give it a classic, earthy edge. Cooking it in the Instant Pot makes it practically foolproof—no oven babysitting, and the meat turns out perfectly cooked every time. It’s a timeless dish with modern convenience.
Ingredients
(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)
3 tablespoons avocado oil
Boneless lamb roast (bone-in leg of lamb also works)
1 teaspoon salt
1½ teaspoons black pepper
2–3 garlic cloves per pound of lamb
1 cup broth (chicken or beef)
1 tablespoon dried rosemary
Directions
I turn the Instant Pot to sauté mode and wait until it shows “HOT.” Then I add the avocado oil.
While the pot heats, I carefully cut small slits all over the lamb roast and press a garlic clove into each one.
I season the entire roast with salt, pepper, and dried rosemary.
Once the oil is hot, I sear the lamb roast fat side down first, browning each side for about 5 minutes to lock in flavor. Then I remove it from the pot.
I place the trivet in the pot, pour in the broth, and return the lamb roast, placing it on top of the trivet.
I secure the lid, set the valve to “seal,” and cook on manual pressure. For boneless roast, I set it for 10 minutes per pound for medium-rare. For bone-in roast, I allow 15 minutes per pound.
Once done, I let the pressure release naturally, which helps keep the meat tender.
After removing the roast, I let it rest for 5 minutes before slicing and serving.
Servings and timing
This recipe serves 4 people.
Prep time: 15 minutes
Cook time: Varies by weight (approx. 10–15 minutes per pound)
Rest time: 5 minutes
Total time (for 2 lb boneless roast): Around 40 minutes
Variations
Sometimes I swap the rosemary for thyme or oregano if I want a different herb profile. For more depth, I use red wine instead of broth. When I’m feeling bold, I rub the roast with a bit of Dijon mustard before searing—it adds a tangy crust. If I have carrots or potatoes on hand, I throw them into the broth around the trivet to make it a one-pot meal.
Storage/Reheating
Leftover lamb stores well in an airtight container in the fridge for up to 3 days. I reheat it gently in a skillet or in the microwave with a splash of broth to keep it moist. It also freezes beautifully for up to 2 months—I slice it first and portion it out for easy meals later.
FAQs
How do I know when my lamb roast is done?
For medium-rare, I cook it 10 minutes per pound (boneless) or 15 minutes per pound (bone-in) and let the pressure release naturally. A meat thermometer should read about 135°F (57°C) before resting.
Can I use a frozen lamb roast?
Yes, but I skip the searing step and add 5–10 extra minutes per pound to the cooking time. Just be sure it fits into the Instant Pot.
Do I have to use a trivet?
I like using the trivet because it keeps the meat out of the broth and helps it cook evenly. If I don’t have one, I place a few thick onion slices at the bottom to lift the roast.
What broth works best?
Both beef and chicken broth work well. I use beef for a richer flavor and chicken when I want something lighter.
What sides go well with lamb roast?
I usually pair it with mashed potatoes, roasted vegetables, or a crisp salad. The pan juices also make a quick sauce or gravy if I simmer them after cooking.
Conclusion
Lamb Roast in the Instant Pot is one of my favorite ways to make a tender, flavorful meal with hardly any fuss. The garlic and rosemary give it a classic flavor, and the pressure cooker keeps everything juicy and fast. Whether it’s a holiday table or a weeknight dinner, this is one recipe that always impresses with minimal effort.
