Once upon time, during the middle ages, rhubarb was considered such a valuable product it was several times more expensive than opium and saffron.
Such was the journey it had to embark on from China, along the Silk Road towards Europe. It would appear the high cost of rhubarb was a matter of logistics, and so, the solution to rhubarb (like many other vegetal and fruit crops that have their genesis far from where they are popular) was to cultivate and acclimatise the plant by clever hybridisation, so it could flourish in the locales where it was desirable.
The name rhubarb is itself a fascinating study in linguistics and humanity, derived from the Latin rhabarbarum – rheum, the plant genus of which rhubarb is a cultivar, and barbarum, the Latin for barbarian.
How it came to far-flung corners of the globe – from Iceland to Queensland – is as predictable as the pairing of rhubarb and strawberries. It tasted great. Rhubarb even inhabited the garden of Thomas Jefferson’s fabled Monticello estate, where he proclaimed the “leaves excellent as spinach”.
We don’t know exactly how Jefferson died, but it was purportedly from a combination of ailments at the age of 83, one of which was kidney infection. Rhubarb leaves are very high in oxalic acid, a nephrotoxin which causes kidney stones – so the moral of this story is nobody, even presidents, should be eating rhubarb leaves.
I read about the origin of rhubarb many years ago, and was surprised that rhubarb does not seem to feature in any Chinese cooking that I was familiar with. That’s easily explained by the fact the Chinese predominantly used only the root in traditional Chinese medicine. I remember thinking, even then, what a big deal was made of this red stalk whose primary use was in pies. That being said, strawberry and rhubarb pie can be a truly splendid – especially when made by Lorraine Godsmark.
I digress.
It illustrated to me what I already started to formulate in my mind: the theory that we all crave the unfamiliar, and wanderlust can be fulfilled (or somewhat abated) by tasting something foreign.
That foreignness is exciting – something we humans all crave despite being creatures of habit. Cultural cuisines shift accordingly, and are ultimately shaped by trends brought back by returning adventurers. By challenging our palates and perception of what is good or delicious, they tempt people out of our creature comforts.
I feel we are at that crux again, as momentarily we aren’t able to travel too far afield. However in Australia we are truly the land of plenty: even in mid-winter we have rhubarb.
This recipe is inspired by Belinda Jeffery, whose delightful cooking class I had the pleasure of attending with my daughter this past weekend.
We refer to Belinda in our household fondly as our FGM (fairy godmother), whose gifts of magical cakes outshine anything Flora, Fauna and Merryweather ever bestowed to Sleeping Beauty. Her baking books are filled with no-fail gems that as much guide as they do inspire.
Rhubarb, apple and brown butter pistachio frangipane upside-down cake
This is a lazy Sunday afternoon bake, when you have nowhere to be and nothing to do – a perfect contemplative time-out to shell the pistachios and brown the apples.
I used a copper tarte Tatin pan, however you can substitute with an oven-safe 25cm diameter high sauté pan or cast iron skillet.
290g cultured butter
8 small apples
1 bunch of rhubarb, or approximately 6-10 stalks
½ cup of packed coconut sugar
1½ tsp Celtic sea salt
2 tbsp water
110g freshly shelled pistachios (you’ll need a food processor to grind these, so they can also be substituted with ground almond or hazelnuts if you don’t have one)
60g buckwheat flour
40g coconut flour
5tbsp brown caster sugar
1½ tsp ground cinnamon
1 tsp baking powder
1 tsp freshly grated nutmeg
3 duck eggs or 4 hen’s eggs
1 scraped vanilla seed pod
Make the brown butter in the pan you will be making the cake in.
To make brown butter you must stay at your stove because it is all about timing. It may look like nothing is happening and then oh dear – it’s burnt. So: DO! NOT! LEAVE!
Add 190 grams of cultured butter into the pan on low-medium heat, swirl to evenly coat the pan and using a spatula, scrape down the sides as it starts to bubble. It will reach a point where it looks like it’s going to bubble out of the pan. Turn off the heat and remove into a medium mixing bowl. Cool and set aside.
Take eight small organic apples (you can use tart varieties or sweet depending on your preference – I like ones with a little bite of sourness). Fresh is the key, as you don’t ever want to cook with a mealy apple. Peel and core. Into the pan place 90g of cultured butter on medium heat, then place the apples face down until evenly brown – depending on the apple size and variety, approximately five to seven minutes. Flip and keep on the heat for another three to five minutes. Remove to cool in a bowl and set aside.
Next, you’re on to the rhubarb. I started by trimming the stalks down roughly to fit the pan. Don’t worry if they are seemingly larger than the pan – go bigger not smaller as they will reduce down. Cook them in the same pan that you browned the apples, making sure there is still butter left. Arrange the rhubarb so it covers the entire surface nicely. Cook it very briefly – just so the stalks are slightly softened to the touch (keep them intact). Remove them to cool into the bowl with the apples.
In the same pan, on low heat, add the packed organic coconut sugar, half a teaspoon of sea salt and two tablespoons of water, stirring until you’ve made a thick caramel. Let it cool and set aside.
Pulse the freshly shelled pistachio with buckwheat flour, baking powder, coconut flour, brown caster sugar, ground cinnamon, freshly grated nutmeg, one teaspoon of sea salt and blend until well incorporated.
Into the brown butter from the first step, beat in with a balloon whisk – one at a time – the duck eggs or hen’s eggs and one scraped vanilla seed pod. Continue to beat until it’s all well blended and looks smooth.
Add the dry flour mix and fold gently. It will look more like a bread consistency than a wet cake mix – do not worry, it will be fine.
Into the pan with the caramel, lovingly arrange first the semi-cooked rhubarb, then the apples, evenly around the pan.
Scrape the batter mix around the pan so that it coats the apples evenly and smooth the top of the cake.
Bake at 175°C for one hour, rotating the cake at 30 minutes to get an even colour. At the one-hour mark, turn off the gas and leave the cake in the oven for another 10 minutes. Take it out of the oven and cool for another 20 minutes.
Turn on to a cake plate.
Make yourself a pot of your favourite tea, slice yourself a generous piece and contemplate the wondrous nature of barbarian cuisine.
