Herb Butter Lamb Rack — Tender, Smoky and Simple
Some cooks remind you to slow down, listen to the fire, and take in the smell of herbs meeting smoke. This Herb Butter Lamb Rack is one of those moments.
It’s simple food done right — a rack of lamb brushed with savoury herb butter, roasted until golden over a bed of crisp white and sweet potatoes. It’s rustic, honest, and full of flavour. The kind of dish that brings people together without fuss or stress.
This recipe came from a craving for something unfussy but rich in flavour. You can prep it in minutes, then let the grill do the work while you enjoy the afternoon. The result is blushing lamb with a buttery crust and golden potatoes that soak up every drop of flavour.
Why You’ll Love This Lamb Recipe
Cooking a lamb rack on the grill brings out its best — tender inside, caramelised outside, and kissed by just enough smoke. The herb butter adds depth and keeps the lamb juicy as it roasts, melting into the meat and dripping down to flavour the potatoes below.
“When you get lamb right, it doesn’t need much else. Smoke, salt, and good butter are all you need.”
This dish works just as well for Sunday dinners as it does for a relaxed BBQ. It’s rich, grounding, and full of warmth — everything that makes live fire cooking feel special.
Choosing Quality Lamb
Start with good meat. I use Macintyre Brook Lamb, a producer known for quality and sustainability. Their grass-fed lamb is leaner, higher in omega-3s, and naturally tender. You can taste the difference — the meat is cleaner, richer, and full of character.
If you’re buying elsewhere, look for grass-fed lamb with bright colour, firm texture, and even marbling. Avoid lamb that feels wet or has a strong smell — fresh lamb should smell clean and mild.
Ingredients
For the Lamb
1 whole lamb rack (about 800g–1kg)
Olive oil (for searing, optional)
For the Herb Butter:
100g unsalted butter, softened
1 tsp sea salt
½ tsp cracked black pepper
½ tsp onion powder
½ tsp garlic powder
1 tsp dried rosemary (or fresh, finely chopped)
½ tsp chicken bouillon powder
For the Potato Base:
2 large white potatoes, peeled and sliced into thick rounds
1 large sweet potato, peeled and sliced to match
Olive oil
Sea salt
Fresh rosemary sprigs (optional)
Serves: 4 Prep time: 15 minutes Cook time: 45 minutes Total: 1 hour
Step 1: Preheat the Grill
Set up your grill for indirect heat. Place the convEGGtor legs up with the stainless steel grid on top. Bring the temperature to 180°C (356°F). Add a couple of chunks of apple or cherry wood to give the lamb a subtle, sweet smoke. This setup creates even heat, allowing the butter to melt slowly into the meat and form that perfect crust. No charcoal grill? No problem. A smoker, or even your oven will work — just use indirect heat and aim for steady temperature control.
Step 2: Make the Herb Butter
Mix all the herb butter ingredients in a bowl until smooth. If you’re preparing ahead, roll it into a log using baking paper and refrigerate. That way, you can slice it easily when ready to cook.
Step 3: Roast the Potatoes
Toss the white and sweet potato slices with olive oil and salt. Spread them in a shallow cast iron pan or roasting tray. Place the tray on the grill and cook indirectly at 180°C for 30 minutes until they begin to soften and brown.
Step 4: Prep the Lamb
Bring the lamb rack to room temperature. Pat it dry with paper towel, then coat the top side generously with the herb butter. If your rack has a thicker fat cap, score it lightly to help the flavours soak through.
Step 5: Combine the Cook
Place the lamb directly on top of the potatoes, bone side down. Close the lid and roast for 20–30 minutes, depending on thickness and your preferred doneness.
Internal temperature guide:
Rare: 48–50°C
Medium rare: 54–56°C
Medium: 60–62°C
Step 6: Finish and Serve
Once your thermometer hits your target, remove the lamb and rest it loosely covered for 10 minutes.
Tips for Perfect Results
The perfect Lamb
Let the lamb rest to keep the juices inside. Score the fat cap before buttering for deeper flavour penetration. Add fresh rosemary or thyme to the potatoes for extra aroma.
For extra crisp edges, sear the lamb quickly over direct heat at the end.
What to serve
Serve your herb butter lamb rack sliced into cutlets over the roasted potatoes. Add a crisp green salad with lemon dressing, garlic green beans, or minted peas on the side. Crusty sourdough is perfect for soaking up those pan juices.
For a full dinner, pair it with a bold red wine such as Shiraz or Cabernet Sauvignon to balance the richness of the lamb.
Variations and Alternatives
If you don’t have sweet potato, use pumpkin or extra white potato.
No chicken bouillon? Add a splash of Worcestershire sauce or skip it entirely.
Fresh herbs always beat dried — parsley, thyme, or oregano all work beautifully.
Why this recipe works
Cooking the lamb rack over indirect heat gives you even roasting and smoky depth without drying the meat. The herb butter creates a crust that seals in moisture and adds layers of savoury flavour. The potatoes underneath catch every drip of butter and juice — they’re as good as the lamb itself.
FAQ
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Yes. Use a fan-forced oven at 180°C and follow the same timings.
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Yes. Store it in the fridge for up to a week or freeze it for a month.
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Ten minutes is ideal. It keeps the juices inside and makes carving easier.
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It should reach 63°C inside and flake easily under gentle pressure.
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Yes, but reduce the cooking time slightly and check temperature early.
