Foie Gras Rocher

Foie Gras (Ferrero) Rocher

It’s my friend Dan’s birthday coming up. So I thought I’d knock up something special for him. He’s nuts about foie gras.

Wait a minute! Foie gras? Nuts?

Foie Gras (Ferrero) Rocher! Quite possibly a mind f*#k.

Yeah. Only one way to find out. And I’ve wanted to do something with a whole foie gras since finishing at Le Cordon Bleu. I mean, just look at it! Don’t you want to give it a cheeky slap? Just me then.

Duck foie gras

To be honest, I didn’t come up with this idea. I found the recipe on Chef Steps, one of my go-to places for information and inspiration. And they have a helpful video too, which I’ve included at the end of this post.

So. First up. Take care of the “Nuts! Ohh hazelnuts.” Do you remember the ad? Basically, toast the hazelnuts.

Toasted hazelnuts

Lobe of foie gras opened up

Back to the liver.

At school, we used foie gras a lot but we only got to watch chef prepare a whole foie gras. My go now.

I separated the 2 lobes with a gentle pull, then carefully opened up each lobe with a spoon handle. Strange, I know. But just like chef showed us. The goal was to locate the veins with minimum invasion and remove them. I felt like a beardie on Time Team, meticulously excavating in the mud. It got messy. Great fun.

Foie gras melts fast so getting touchy-feely with your hands is strictly off limits. It demands foreplay. No poking and prodding. One must caress the foie—albeit with a spoon handle. Patience. Care. Attention. Doing it this way, rather than cutting around with a knife, makes it easier to fold a lobe back together.

Main vein through the foie gras

Reconstituting the two lobes of foie gras after removing the veins

The creamy centre of the rocher is a foie gras ganache.

To make this, the foie gras was cooked sous vide for 30 minutes at 54C. So much fat came out. That’s flavour, baby. Meanwhile double cream was infused with carefully weighed amounts of sugar, salt and curing salt. Foie gras takes plenty of seasoning and, given the price, it’s something you want to get right. So it’s done by weights. More double cream was slowly heated with gelatine until it was melted and fully incorporated.

I learned something new today. Gelatine comes in different strengths. Who knew? I needed 160 Bloom but neither the gelatine leaves nor the powder I had specified a strength. Fail. It’s only £20’s worth of foie gras. Having looked it up, a higher bloom means higher melting and gelling points and a shorter gelling time.

Then over to The Beast—my new commercial blender.

Foie gras vac-packed

Sous vide foie gras

The liver and fat, plus the salted and jellied creams went into my Vita-Prep 3. Whizzz. I swear the building shook. Look at that texture. It looks like melted Caramac. Mmm. I was taking no risks and still passed the ganache through a fine sieve before loading up a piping bag.

Blend the foie gras, salt mixture, gelatine and double cream

Pass the foie gras ganache through a fine sieve

The ganache was piped into hemisphere moulds.

Tip: To fill a mould evenly, place the nozzle in centre near the bottom of the mould and squeeze. Keep the nozzle centred. Let the mould fill around nozzle, then slowly start pulling up. Gently drop the mould onto the work surface to remove any air bubbles.

Whole toasted hazelnuts were pushed half way into half the hemispheres. The mould was then tightly wrapped in cling film and put in the freezer for an hour or so.

Once completely frozen, a small crater was created at the centre of each hemisphere without a hazelnut. A fire gun on low was used to melt their flat surfaces. The hemispheres containing the nuts were then placed on top and pushed down gently. The balls were returned to the freezer for another hour. Once hardened up, I used a turning knife to tidy up the seams. Best to wear rubber gloves when handling the frozen foie gras. It doesn’t take much warmth to start softening it.

Chopped and sieved hazelnuts

During all the freezer action I chopped and sieved the remaining hazelnuts, ending up with 3 grades. The fine dust was reserved for some other use.

Dark chocolate was melted in a Bain Marie and maintained around 55C. The balls were double dipped in the chocolate with a freeze in between. Liquid nitrogen would’ve been handy. Or a blast chiller. Following the second dip in chocolate, each ball was rolled around in a bowl containing the hazelnut nibs. No fingers involved. It was sometimes necessary to gently heat the chocolate with the fire gun while rolling the ball around.

I ran out of the medium hazelnut nibs so ended up using the larger size too. But it was quite nice to be able to try both.

Foie Gras Rocher with the larger hazelnut nibs on the left

I think they turned out really well. They look pretty good and actually taste pretty good too. The sweet and salty ganache is wonderfully contrasted by the bitterness of the dark chocolate. And the super creamy texture is only revealed after the crack of chocolate shell and the crunch of hazelnuts. And they’re a different eating experience fresh out of the fridge versus having warmed up a little. I prefer the latter. I can definitely see them on a tasting menu, or as a left field appetiser. Maybe even an alternative chocolate truffle to enjoy with your after dinner espresso. I need to try that.

Dan seemed to like them. Win.

Here’s that video from ChefSteps.

Did you notice I have exactly the same blender and hemisphere mould? When I watch these videos I’m always on the look out for new kitchen tools. Now I want a bandsaw. Do you think Roberta would notice? And how cool is that water bath with ping pong balls? What’s that all about? I had to investigate. The balls minimise evaporation.