Roast Rump Cap with Sauce Verte

Lunch | Australian

Prep time: 24 min Cook time: 2 min Servings: 6

Rump cap (picanha) is a cut I keep coming back to for big group cooks. It has a thick fat cap on one side that renders during the low-and-slow cook and bastes the meat from above, giving you deep flavour without a lot of hands-on work. This recipe uses a kombu-based seasoning from the team at Fallow restaurant in London, applied the night before so it has time to work into the surface.

Sauce verte is the French take on green sauce: fresh herbs, mustard, creme fraiche and olive oil, blended smooth. It’s sharp, herby and rich, and it cuts through the fat of the beef well. The whole thing takes two minutes in a blender. The rest of the recipe is designed to be prepped ahead.

The seasoning goes on the night before, the pre-cook can be done up to 5 hours before serving, and the beef holds its temperature in a good esky for the full window. That makes this viable for a Christmas lunch where you need the BBQ free for other things, as the final sear is only about 6 to 8 minutes.

Ingredient Notes

Rump cap (picanha): The rump cap is the thick triangular muscle that sits at the top of the rump, covered on one side by a thick fat cap. That fat is the defining feature of the cut: it renders during the cook, bastes the meat and is the main source of flavour. Ask your butcher for a whole rump cap or picanha. If you can’t find it, tri-tip is the closest alternative in terms of shape and cook method. Top sirloin works but won’t have the same fat coverage. For a budget version, bolar blade roast is a reasonable substitute, though it needs a longer cook and different handling.

Kombu: Kombu is dried Japanese sea kelp and one of the primary natural sources of glutamates, the compounds responsible for savoury, umami flavour. For this seasoning blend it’s toasted and ground, which transforms the marine quality into a deeper, more savoury note that reads as complexity rather than seafood. You’ll find dried kombu sheets at Asian grocery stores and specialty food shops. Toast a sheet in a dry pan over medium heat until fragrant and slightly crisped, then blitz in a spice grinder or high-powered blender until fine. If you can’t source it, omit it and increase the other spices slightly, or use your favourite steak seasoning blend instead.

Creme fraiche: Creme fraiche is a cultured cream with a slightly tangy, sour flavour and a thick, stable consistency. In the sauce verte it adds richness and acts as a partial emulsifier alongside the olive oil, giving the sauce a creamier body than a straight herb oil. It holds up well in the blender without splitting. You’ll find it in the dairy section of most supermarkets. Full-fat sour cream is a good substitute if you can’t find it. Don’t use regular pouring cream as it won’t give you the right consistency or acidity.

Equipment

Chopping board
Chef’s knife
Small bowl
Wire rack over tray
Hooded BBQ or oven
Meat probe or instant-read thermometer
Esky or insulated box
Blender or food processor
Tongs

Ingredients

2kg beef rump cap (picanha)
Kombu Seasoning
¼ cup ground toasted Kombu
1½ tbsp smoked paprika
2 tsp ground coriander
2 tsp ground cumin
1 tsp cayenne
1 tsp onion powder
1 tsp garlic powder
1 tsp sea salt
1 tsp ground black pepper
1 tsp MSG
Sauce Verte
1 bunch basil, leaves picked
1 bunch mint, leaves picked
1 bunch tarragon, leaves picked
1 bunch parsley, leaves picked
1 tbsp dijon mustard
60g (¼ cup) creme fraiche
juice of 1 lemon
125ml (½ cup) olive oil
sea salt, to season

Directions

Prep the beef
Trim any excess silverskin from the beef and trim back the fat cap if too thick.
Combine all the ingredients for the kombu seasoning in a small bowl and mix well.
Place the beef on a wire rack over a tray and rub the kombu seasoning onto all sides.
Set aside in the fridge uncovered overnight.
Pre-cook the beef
Preheat a hooded BBQ (or oven) to 100°C, with one burner turned onto low.
Place the beef, fat cap side down, on the resting rack the furthest away from the heat, but with the thicker end of the beef towards the heat.
Close the lid and cook for 2 hours, until the internal temperature reaches 48°C (check with a meat probe after 1 hour).
Remove from the BBQ and transfer to a wire rack over a tray. Cover with a piece of baking paper then wrap the tray in foil.
Place the beef in an esky and rest for at least 2 hours, or up to 5 hours.
Make the sauce verte
Combine all the herbs, mustard, creme fraiche, lemon juice and olive oil in a blender. Season with salt and blend until smooth.
Sear the beef and serve
Preheat the BBQ flat plate over high heat. Remove the beef from the esky and unwrap.
Place the beef, fat cap side down, on the plate and cook with the lid down for 2 minutes, until well seared, then turn over and cook the underside with the lid closed. Cook for a further 2-3 minutes, until well seared on all sides.
Transfer the beef to a wire rack over a tray and rest for a few minutes until it’s cool enough to handle.
Carve the beef into slices and serve with the sauce verte on the side.

Recipe notes

Chef Tips

Use an esky to hold the beef between the pre-cook and the sear

After the pre-cook, the beef goes into an esky wrapped in foil and it will hold its internal temperature for up to 5 hours. This isn’t just a resting step: it’s what makes the whole recipe workable for a group. You can pre-cook the beef in the morning, put it in the esky, then do the final sear when you’re ready to eat. The beef will still be warm throughout when you pull it out, and the short sear on the flat plate is only there to crust the outside, not cook the inside.

Start the sear fat cap side down

The fat cap is thick and needs longer to render and crisp than the lean sides of the beef. Starting fat cap side down on a very hot flat plate with the lid closed means the fat gets a full 2 minutes of direct high heat contact before you move to the other sides. You’re looking for deep golden colour and visible rendering across the surface. If the fat cap isn’t crisped well, the eating experience of those outer slices is less enjoyable. Don’t rush this part.

Storage

Leftover beef keeps in an airtight container in the fridge for up to 4 days. If you’re not eating it all at once, carve only what you need and keep the rest whole: uncut beef holds moisture better and lasts longer. Cold leftover rump cap is excellent in sandwiches with the sauce verte. The sauce verte keeps covered in the fridge for up to 3 days.

FAQs

Can I make this ahead of time? Yes, and it’s designed for it. Season the beef the night before and refrigerate uncovered. The pre-cook can be done up to 5 hours before serving and the beef held in an esky. The sauce verte can be made on the morning and kept in the fridge. The final sear is only 6 to 8 minutes, so it’s a short finish when you’re ready.

Can I cook this without a hooded BBQ? Yes. The pre-cook works in an oven set to 100°C on a wire rack over a tray. For the final sear, use a very hot cast iron skillet on the stovetop: fat cap side down for 2 to 3 minutes, then turn and sear the remaining sides. You won’t get quite the same char as a flat plate, but the result is very close.

What can I use instead of kombu? If you can’t find kombu, omit it and use your favourite steak seasoning blend in place of the full spice mix. Alternatively, keep the same proportions of smoked paprika, cumin, coriander, garlic powder, onion powder, cayenne and salt from the recipe and leave out the kombu. The seasoning will still be good; you just won’t have that extra layer of umami depth in the crust.