Rhubarb White Chocolate Elderflower Tart

The first time I made this tart was for a friend's birthday in late April. I'd bought rhubarb at the farmers market impulsively, those gorgeous pink stalks calling to me from across the stall. The combination seemed unusual but something about pairing tart rhubarb with sweet white chocolate just clicked. Every bite transported me to an English garden in full bloom.

My grandmother had rhubarb growing in her garden and always warned us about the toxic leaves. I remember watching her painstakingly trim every stalk, teaching me that patience in the kitchen pays off. Now whenever I work with rhubarb, I'm transported back to her tiny kitchen with the windows open, smelling that distinctive tangy aroma.

Ingredients

• 200 g all-purpose flour: The foundation for a tender crust that holds everything together beautifully
• 100 g cold unsalted butter, cubed: Keep it ice cold for that flaky texture that makes tarts so irresistible
• 50 g powdered sugar: Adds just the right sweetness without the grit of granulated sugar
• 1 large egg yolk: Binds the dough while adding richness and golden color
• 1–2 tbsp cold water: Only add enough to bring the dough together, don't overwork it
• Pinch of salt: Enhances all the flavors and balances the sweetness
• 150 g white chocolate, finely chopped: Use a good quality brand for the smoothest melting results
• 250 ml heavy cream: Creates that luxurious custard texture we're all after
• 50 ml whole milk: Lightens the custard just slightly while keeping it rich
• 60 ml elderflower cordial: The secret ingredient that makes everything taste like spring
• 3 large egg yolks: These give the custard its silky smooth consistency
• 30 g granulated sugar: Just enough to balance the white chocolate's sweetness
• 1 tsp vanilla extract: Pure extract, never imitation, for the best flavor
• 300 g rhubarb, trimmed and cut into 5 cm batons: Choose stalks that are bright pink and firm
• 60 g granulated sugar: Helps tame rhubarb's natural tartness during roasting
• Zest of 1 lemon: Brightens everything and makes the rhubarb sing
• 2 tbsp elderflower cordial: An extra flourish that ties everything together

Instructions

Prepare the Tart Crust:

Pulse flour, butter, powdered sugar, and salt in a food processor until the mixture looks like coarse breadcrumbs.

Bring the Dough Together:

Add the egg yolk and 1 tablespoon cold water, pulsing until the dough just starts to clump together. Add more water only if needed, you want it to hold shape when pressed.

Chill the Dough:

Shape into a disc, wrap tightly, and refrigerate for 30 minutes. This rest period is crucial for preventing shrinkage during baking.

Line the Tart Tin:

Roll out on a floured surface and carefully transfer to a 23 cm tart tin. Press into the edges, trim any excess, and chill again for 15 minutes.

Blind Bake the Shell:

Preheat oven to 180°C. Line with parchment, fill with baking beans, and bake for 15 minutes. Remove beans and parchment, then bake 5–7 more minutes until golden all over.

Warm the Cream Mixture:

Heat cream and milk in a saucepan until steaming but never boiling. You want it hot enough to temper the eggs but not scramble them.

Prepare the Egg Base:

Whisk egg yolks, sugar, and vanilla until pale and slightly thickened. This takes about 2 minutes of enthusiastic whisking.

Temper and Combine:

Slowly pour hot cream into yolks while whisking constantly. Return to low heat and stir until it thickens enough to coat a spoon.

Add the Signature Flavors:

Remove from heat and stir in white chocolate and elderflower cordial until completely smooth and glossy.

Set the Custard:

Pour into cooled tart shell and refrigerate for at least 1 hour. The patience pays off with perfectly set filling.

Roast the Rhubarb:

Preheat oven to 190°C. Arrange rhubarb in a single layer, sprinkle with sugar, add lemon zest and elderflower cordial.

Tender Roast:

Cover with foil and roast for 15 minutes, then uncover and roast 5–8 more minutes. You want it tender but still holding its shape.

Final Assembly:

Arrange cooled rhubarb over set custard in any pattern that pleases your eye. Brush with extra cordial for a professional looking finish.

Pin It

This tart became my go to for spring celebrations after serving it at my mother's retirement party. She took one bite and declared it better than anything she'd had in Paris. Now it wouldn't be spring without making it at least once.

Make Ahead Magic

The beauty of this tart is that each component can be prepared in advance. I often make the crust and custard a day ahead, then simply roast the rhubarb and assemble right before serving. The flavors actually develop and improve overnight.

Rhubarb Selection Secrets

Look for stalks that are bright pink to red, avoiding any that look green or dried out. Thinner stalks tend to be more tender and require less roasting time. Field rhubarb has the most intense flavor, while hothouse varieties are milder and sweeter.

Serving Suggestions

This tart shines brightest when served slightly chilled but not ice cold, about 30 minutes out of the refrigerator. The custard becomes beautifully creamy and the rhubarb's flavor truly pops at this temperature. I love serving it with a small glass of elderflower cordial topped with sparkling water.

• A dollop of crème fraîche cuts through the richness nicely
• Toasted pistachios add lovely crunch and color contrast
• Serve within 24 hours as the crust will eventually soften

Pin It

There's something deeply satisfying about serving a dessert that looks this impressive while being entirely doable. Spring will never taste the same again.

Recipe FAQs

→ Can I make this dessert ahead of time?

Yes, this tart is designed to be made in advance. The crust and custard can be prepared, and the rhubarb roasted, then assembled and chilled until serving.

→ What can I use if I don't have elderflower cordial?

For the custard, you could substitute a floral liqueur or omit it, slightly increasing the vanilla extract. For the rhubarb, lemon juice and a little extra sugar will still provide a good balance.

→ How do I prevent a soggy tart crust?

Blind baking the crust thoroughly until golden brown, as instructed, is crucial. Ensure it's completely cooled before pouring in the custard filling.

→ Can I use frozen rhubarb?

Yes, you can use frozen rhubarb. Thaw it completely and drain any excess liquid before roasting to prevent the dish from becoming watery.

→ How long does this tart last?

Stored properly in the refrigerator, this tart will remain fresh and delicious for 2-3 days. Cover loosely to maintain its quality.

→ What's the best way to serve this dessert?

Serve chilled, perhaps with a dusting of powdered sugar or a side of freshly whipped cream. It pairs wonderfully with a light dessert wine or an elderflower spritz.