Spiced Sweet Potato Mont Blanc
Words & Photography by Sophia Real
When the other new contributing editors of Food&_ and myself were discussing what dishes to feature for Thanksgiving week, we quickly agreed we wanted to stay true to the traditional ingredients featured in a Thanksgiving feast but to come up with new recipes based around them. At first, I kept on staring at an empty page when trying to come up with ideas – I did not grow up celebrating Thanksgiving and the one Thanksgiving I spent at my friend Laura’s in Minneapolis was but a snapshot of what Thanksgiving entails. But after a few days of brainstorming, poring over my cookbooks and researching Thanksgiving dishes old and new, I happily settled on a Spiced Sweet Potato Mont Blanc.
Mont Blanc is a classic French dessert, traditionally featuring chestnuts and whipped cream with either a meringue or buttery shortbread base. In a nod to the marshmallow topped sweet potatoes found on many Thanksgiving tables, this Mont Blanc hides a generous dollop of homemade marshmallow fluff underneath a mountain of sweet potato cream swirls laced with the same spices used for another Thanksgiving classic: pumpkin pie.
Although new to me, I quickly discovered that a sweet potato based Mont Blanc is not such a new idea at all, as it is a fairly common dessert in French pastry-obsessed Japan. And if you can get your head around the idea of eating a sweet potato-based dessert, then I think you will like this dessert as much as I do (and I like it so much I may have eaten one Mont Blanc each for lunch and dinner one day when I was testing this recipe).
Spiced Sweet Potato Mont Blanc
Note: This dessert is not particularly difficult and both the tartlets and the spiced sweet potato mash can be made in advance. All that remains to be done on the day you want to serve is to make the marshmallow fluff, and, while the marshmallow fluff is setting, you whip the cream and fold this into the spiced sweet potato mash before quickly assembling the Mont Blanc.
Instead of the 4 individual tartlets I made here, you could also make one large Mont Blanc, adjusting the baking times accordingly.
For the Brown Sugar Sweet Pastry
60g butter, at room temperature
30g caster sugar
20g brown sugar
1 yolk Pinch of salt
120g wholegrain spelt flour
For the Marshmallow Fluff
2 egg whites
100g caster sugar
For the Spiced Sweet Potato Cream
300g peeled sweet potato, cubed
4 tsp maple syrup
Pinch of cinnamon
Pinch of ground ginger
Pinch of nutmeg
Pinch of salt
120ml whipping cream
For the Brown Sugar Sweet Pastry, cream the soft butter together with the caster sugar and the brown sugar until light and fluffy (this should take ca. 5 minutes). Add the egg yolk and beat to incorporate. Next, whisk the pinch of salt into the wholegrain spelt four and dump the flour on to the butter mixture in one go. Using a wooden spoon or a spatula stir the flour into the butter mixture (the dough will appear very crumbly at first, but will eventually come together to form a cohesive dough). Wrap the dough in cling film, flatten into a disk and place in the fridge for at least 1 hour to firm up.
Pre-heat the oven to 200 degrees Celsius. Remove the dough from the fridge and break into chunks. Bring the chunks back together and knead until the dough is pliable. On a lightly floured surface roll out the dough to ca. 3mm thickness. Line 4 tartlet pans with the dough and cut off any excess dough with a sharp knife (you may have to re-roll the dough to line the last 2 tartlet pans). Blind-bake the tartlets for 15 minutes. Bake for a further 5-10 minutes until the pastry is crisp and starting to colour. Set aside to cool to room temperature.
For the Spiced Sweet Potato Cream, cook the sweet potato cubes in boiling water until soft (ca. 10-15 minutes). Drain and mash with a potato masher or potato ricer. Pass through a fine sieve and weigh out 240g and place in a bowl. Add the maple syrup and season with the cinnamon, ground ginger, nutmeg and salt (I would start with a pinch of each of cinnamon, ground ginger and nutmeg and tasting before adding more – you want the sweet potato cream to be subtly spiced, not more). Cover the bowl and place in the fridge until you want to assemble the Mont Blanc.
For the Marshmallow Fluff, place the egg whites and sugar in a large bowl suspended over a pot of simmering water, making sure the bowl does not touch the water. Whisking constantly, heat the mixture until the sugar is dissolved and the mixture has turned opaque and started to thicken (this should take ca. 5-10 minutes). Remove the bowl from the pan and, using an electronic whisk, beat the mixture until it has tripled in volume and pulls away from the sides of the bowl.
Transfer the Marshmallow Fluff to a piping bag with a large round tip and pipe a large dollop of Marshmallow Fluff into the centre of each tartlet (alternatively you can use two tablespoons to do this). Set aside until the Marshmallow Fluff has set (ca. 30 minutes).
While the Marshmallow Fluff is setting, whip the cream until stiff. Fold 1/2 of the whipped cream into the sweet potato mash to loosen it, before carefully folding in the remaining whipped cream.
Transfer the Spiced Sweet Potato Cream to a piping bag with a fairly small round tip (ca. 2-3mm in diameter). Starting from the outside of the tartlets pipe swirls of Spiced Sweet Potato Cream all around the Marshmallow Fluff, adding more and more layers the closer to the centre of the tartlets you get so you end up with little mounds on each tartlet.
Keep in the fridge until ready to serve.
Mont Blancs are best eaten on the day they are made, when the pastry shell will be nice and crisp.