Of the lesser loved vegetables I feel celeriac, in particular, is underappreciated when it comes to delicious mealtime inclusions. Despite being rich in nutrients many find its knobbly, odd-shaped appearance a little off-putting, and when it's oft described as being 'bulbous' and 'turnip-like' we're certainly not doing its image any favours. But delve beneath the rough exterior and you'll find a beautiful, creamy flesh that tastes a little bit like celery, but with a sweet nuttiness that adds a real depth of flavour.
Most commonly used in a remoulade or gratin (and notably delicious when roasted), celeriac pairs beautifully with all things rich and creamy, and given its inherent, subtle sweetness I was interested to see how it would perform when featured in an unconventional dessert.
Inspired by Mark Diacono's recipe for celeriac crème brûlée and agreeing with his sentiments regarding messing with the classic version I instead decided on tarts, filling some crumbly, fennel-laced crusts with a rich celeriac lemon thyme custard and finishing them off with a dark caramel pine nut praline.
For me, it was a combination that worked perfectly. I like sweets that aren't overly so, and enjoyed the surprise of an unexpected, albeit delicious flavour. The inclusion of lemon thyme really lifts things without overpowering the subtleness of the celeriac, and the praline rounds everything out nicely while providing a nice crunch to balance the soft custard below.
Root vegetables work wonders in sweets—as carrot and chocolate beetroot cakes have long proved—but if you've never had the pleasure of celeriac, or are just looking for something different to try, then why not give these lovely little rustic numbers a go?
CELERIAC LEMON THYME TART (Inspired by recipes from Mark Diacono's A Year at Otter Farm)
For the fennel pastry:
- 160 g plain flour
- 20 g semolina
- A pinch of salt
- 1 tsp fennel seeds, lightly ground
- Finely grated zest of half a lemon
- 40 g caster sugar
- 130 g butter, cold and cubed
- 1 egg, lightly beaten
For the celeriac custard:
- 25 g butter
- 180 g peeled celeriac, sliced and cut into small pieces
- 100 ml milk
- 4 egg yolks
- 70 g caster sugar
- 250 ml double cream
- ½ vanilla pod
- 4 sprigs lemon thyme
For the pine nut praline:
- 150 g caster sugar
- 2 Tbsp water
- 150 g pine nuts
To make the tart shells, mix together the dry ingredients and then rub in the butter until the mixture resembles breadcrumbs. Add enough egg to bring the pastry together (approximately 30 ml), form into a disc, wrap in cling film and refrigerate for 30 minutes.
Roll the pastry out to a thickness of 5-mm, cut rounds and line six well-buttered 3-inch tart tins. Chill for 30 minutes then line and fill with rice/baking weights and blind bake in an oven preheated to 180°C for 20 minutes. Remove the linings and bake for a further 10 minutes, until the edges and underside are golden. Allow to cool for 10 minutes before removing the tart shells from their tins and leaving to cool completely.
To make the filling, melt the butter in a small pan over low heat and cook the celeriac for about 10 minutes, until it begins to soften. Add the milk and simmer for a further 10 minutes until tender then puree until smooth, adding a few splashes more milk if necessary.
Combine the cream, vanilla and lemon thyme in a small pan and bring to the boil. While you're waiting, whisk together the yolks and sugar until combined. Strain the cream over the yolks, whisking as you pour, then whisk in the celeriac puree and leave for a few minutes to cool. Pour into the pre-baked tart shells and bake at 160°C for 20-25 minutes until the custard has just set (there should still be a slight wobble in the centre of the tarts). Leave to cool then refrigerate for a few hours before serving.
Meanwhile, prepare the pine nut praline by melting the sugar and water over low heat to dissolve, then allow to boil for 4-5 minutes until it reaches 110°C (just starting to turn light caramel in colour). Stir in the pine nuts, turn down the heat and stir gently until the sugar redissolves to a caramel, around 10 minutes. Carefully pour onto a tray lined with greased foil, smooth out the caramel using the back of a fork and then leave to cool. Once set, break the praline into chunks and pound with a mortar and pestle to the desired consistency (I like a mix of fine powder and small chunks of nutty caramel).
To serve, sprinkle each tart with a big pinch of praline. Makes 6 three-inch tarts, some extra filling (which can be cooked in a ramekin covered in foil using a bain marie, if desired), and a lot of extra praline crumble (no complaints here!).