BBQ Lamb Rump

Lunch | Australian

Prep time: 10 min Cook time: 35 min Servings: 4

Crack out the BBQ, we're grilling some lamb rump and serving it crispy smashed potatoes, grilled asparagus and a radicchio salad. This one is great for a weeknight dinner or a nice Sunday lunch.

The fat cap gets scored in a diamond pattern before going on the grill, which lets the fat render properly and crisps up to something really special. A high-heat sear on the fat side first, then cooking to an internal temperature of 54°C (129°F), gives you medium-rare meat that’s tender and full of flavour.

The herb dressing is made with mint, tarragon, honey, dijon and lemon, blended until smooth, and it works as both a salad dressing and a sauce for the lamb. Grilled asparagus and spring onions alongside a radicchio salad makes this a complete plate that’s well suited to a weeknight dinner or a relaxed Sunday lunch. The whole thing is on the table in under an hour.

Ingredient Notes

Lamb rump: Lamb rump is a well-flavoured, moderately priced cut that responds well to high heat cooking. The fat cap on top is what makes it so good on the BBQ, it renders and crisps in a way that most other cuts can’t match. I look for 200g rumps from the butcher, sized evenly so they all hit temperature at the same time. Ask your butcher to leave the fat cap on.

Radicchio: Radicchio is a bitter Italian chicory with a deep red colour that holds up well to a bold dressing. It adds a welcome bitterness that balances the richness of the lamb and the sweetness of the honey dressing. If you can’t find it, Belgian endive or witlof works similarly. Tear the larger outer leaves into chunks and leave the smaller inner leaves whole.

Tarragon: Fresh tarragon has a distinctive anise-like flavour that pairs exceptionally well with lamb. It’s the herb that makes this dressing taste different from a standard herb vinaigrette. If you can’t find fresh tarragon, a small amount of dried will work, but use it sparingly as the flavour is more concentrated. Remove any tough stems before blending.

Equipment

Chopping board
Chef’s knife
BBQ with grill plate
Instant-read thermometer
Stick blender or small food processor
Large bowl (for the salad)
Serving platter

Ingredients

4 x 200g lamb rump
sea salt, for seasoning
Salad
1 bunch mint, leaves picked
1 bunch tarragon, leaves picked
2 tsp honey
2 tsp dijon
80ml olive oil, plus extra for drizzling
juice of 1 lemon
10 spring onions, trimmed
2 bunches asparagus, trimmed
1 radicchio, leaves separated

Directions

Cook the lamb
Score the fat cap of the lamb in a small diamond pattern. Season all sides generously with salt.
Preheat the BBQ grill to high heat. Cook the lamb for 6-8 minutes, until browned on all sides.
Transfer to the resting rack above the grill, offset to the burners that are still on.
Reduce the BBQ heat to medium and close the lid, until the internal temperature of the lamb reaches 54°C (129°F).
Make the salad dressing
Combine half of the herbs with the honey, dijon, oil and lemon juice in a tall jug.
Season with salt and puree with a stick blender until smooth.
BBQ the salad vegetables
Chop the asparagus and spring onions into 6cm lengths. Toss in some oil and season with salt.
Check if you’re lamb is at 54°C (129°F), and set it aside to rest and increase the BBQ grill heat to high.
Cook the asparagus for 3-4 minutes and spring onions for 2 minutes, turning, until charred and softened. Transfer to a tray.
Assemble and serve
Chop the larger radicchio leaves into chunks and place in a large bowl. Add the spring onions and asparagus, remaining herbs and drizzle with half the dressing. Toss gently to combine.
Arrange the salad on a serving platter. Slice the lamb into thin slices, then add on top of the salad. Drizzle with the remaining dressing. Serve with some crispy potatoes.

Recipe notes

Chef Tips

Score the fat cap deeply

The scoring isn’t just about presentation. Cutting through the fat cap in a diamond pattern lets the fat render from the inside out as it cooks, which prevents the cap from curling and ensures even contact with the grill. Use a sharp knife and cut through the fat all the way down to (but not into) the meat.

Rest the lamb before slicing

Lamb rump needs at least 5 minutes of resting after it comes off the heat, and longer if the pieces are large. This is the step that keeps the meat juicy. If you slice it immediately, the juices run straight out. Resting on a rack above the residual heat of the BBQ keeps it warm while it relaxes without continuing to cook.

Storage

Store leftover lamb slices in an airtight container in the fridge for up to 3 days. The herb dressing can be stored separately in a jar for the same time. I’d recommend reheating the lamb in a hot pan for 1-2 minutes per side rather than in the microwave, which tends to make it tough and grey.

FAQs

Can I make this without a BBQ? Yes. A cast iron grill pan or heavy-based frying pan over high heat works well. Get the pan very hot before the lamb goes in, fat side down first, and press it down gently to ensure full contact. Finish in a 200°C (390°F) oven if needed to reach temperature without burning the exterior.

What does 54°C internal temperature look like? That’s medium-rare for lamb, which means a pink, warm centre. Use an instant-read thermometer for accuracy and pull the lamb just before it hits your target, as the temperature will continue to rise by a few degrees while it rests. If you prefer medium, aim for 60°C (140°F).

Can I use a different cut of lamb? Yes. Lamb backstrap (eye of loin) is the closest substitute and cooks in a similar time. Lamb cutlets also work but cook much faster, so reduce your cooking time significantly and watch the temperature closely. I’d avoid lamb leg steaks here as they’re often uneven in thickness and harder to cook to temperature consistently.