Rhubarb White Chocolate Elderflower Tart

The scent of elderflower always takes me straight back to late May, when the hedgerows are blooming and the kitchen smells like sunshine bottled up in syrup. I made this tart on a whim one Saturday afternoon, mostly because I had too much rhubarb and a bottle of elderflower cordial I kept meaning to use. The combination turned out to be one of those happy accidents that gets requested every spring now. White chocolate might seem like an odd partner for rhubarb, but trust me, its creamy sweetness is exactly what the tartness needs.

I brought this to a garden party once, and it sat on the table looking almost too pretty to cut into. The pink rhubarb glowed against the pale custard, and everyone hesitated before the first slice. Once we started, though, the whole tart vanished in minutes. Someone asked if I'd trained in Paris, which made me laugh because I'd been cursing at my pastry dough just that morning.

Ingredients

• All-purpose flour: The foundation of your tart crust, and using cold ingredients is the secret to keeping it flaky and crisp instead of tough.
• Cold unsalted butter: Cubed and chilled so it creates those lovely layers in the pastry; if it melts before baking, you lose the texture.
• Powdered sugar: Dissolves more smoothly into the dough than granulated and gives a tender, melt-in-your-mouth quality.
• Egg yolk: Adds richness and helps bind the dough without making it too wet or sticky.
• White chocolate: Choose a good quality brand with real cocoa butter, not the candy-aisle stuff, or the custard will taste artificial.
• Heavy cream and whole milk: Together they create a custard that is rich but not overwhelmingly heavy, with just the right silkiness.
• Elderflower cordial: This is where the magic happens; it brings a subtle floral sweetness that makes people ask what that lovely flavor is.
• Egg yolks: The thickening agent for your custard, and whisking them with sugar first prevents scrambling when you add the hot cream.
• Rhubarb: Look for firm stalks with bright color; avoid any that are limp or browning at the ends.
• Lemon zest: Brightens the rhubarb and keeps it from tasting one-dimensional or too sweet.

Instructions

Prepare the Tart Crust:

Pulse the flour, cold butter, powdered sugar, and salt in a food processor until it looks like coarse breadcrumbs, then add the egg yolk and just enough cold water to bring it together without overworking it. Roll it out on a floured surface, press it gently into your tart tin, chill it so it holds its shape, then blind bake with parchment and beans until golden and crisp.

Make the Custard Filling:

Heat the cream and milk until steaming, then slowly whisk it into your egg yolk mixture so you temper the eggs without scrambling them. Stir over low heat until the custard thickens just enough to coat the back of a spoon, then fold in the white chocolate and elderflower cordial until smooth and glossy.

Roast the Rhubarb:

Lay the rhubarb batons in a single layer, sprinkle with sugar, lemon zest, and elderflower cordial, then cover with foil and roast until tender but still holding their shape. Let them cool completely before arranging on the tart so they don not melt the custard.

Assemble the Tart:

Once the custard has set in the fridge, arrange the cooled rhubarb on top in whatever pattern makes you happy. A light brush of elderflower cordial adds shine and an extra hint of flavor.

Save

This tart has become my go-to when I want to impress without losing my mind in the kitchen. It sits quietly in the fridge, looking elegant and tasting even better after a night of the flavors mingling together. There is something deeply satisfying about pulling it out, already perfect, while everyone else is still fussing over last-minute things.

Choosing Your Rhubarb

I learned the hard way that not all rhubarb is created equal. The thin, green stalks can be stringy and too tart, while the thicker pink ones roast beautifully and keep their shape. If you can find forced rhubarb in early spring, with its bright pink color and tender texture, grab it because it is truly special. Just avoid any stalks that feel bendy or look dried out at the ends.

Working With White Chocolate

White chocolate can be temperamental, seizing up if it gets too hot or turning grainy if the custard is not smooth enough. I always chop it finely so it melts quickly and evenly into the warm custard without needing extra heat. If your custard looks a bit lumpy after adding the chocolate, a quick pass through a fine sieve will save it and give you that glossy, professional finish.

Make-Ahead Magic

One of the best things about this tart is how well it holds up in the fridge. I have made it two days ahead for a dinner party, and it tasted even better after the flavors had time to settle and deepen. The custard stays creamy, the crust stays crisp if you store it properly, and the rhubarb keeps its lovely texture.

• Store the assembled tart loosely covered in the fridge for up to two days before serving.
• If making the components separately, keep the baked crust in an airtight container at room temperature and assemble the day of serving.
• Leftover slices keep well for three days, though the crust may soften slightly over time.

Save

This tart reminds me that spring does not last long, so we might as well make the most of it while the rhubarb is blushing and the elderflower is blooming. I hope it becomes one of those recipes you pull out when you want to feel a little bit fancy, without all the fuss.

Recipe Questions & Answers

→ Can I make this tart ahead of time?

Yes, this is an excellent make-ahead dessert. Prepare the tart shell and custard filling up to 24 hours in advance. Roast the rhubarb and assemble the tart up to 4 hours before serving for best results.

→ What can I substitute for elderflower cordial?

If elderflower cordial is unavailable, use a light floral honey diluted with water, or substitute with orange blossom water. You can also omit it and add extra vanilla extract for a simpler flavor profile.

→ How do I prevent the tart crust from becoming soggy?

Blind baking the crust until golden is essential. Let it cool completely before adding the custard filling. You can also brush the baked shell with a thin layer of melted white chocolate before filling for extra protection.

→ Can I use frozen rhubarb instead of fresh?

Fresh rhubarb works best as it holds its shape better when roasted. If using frozen, thaw completely and pat dry before roasting. Reduce roasting time slightly as frozen rhubarb tends to be softer.

→ How should I store leftover tart?

Cover the tart loosely with plastic wrap or store in an airtight container in the refrigerator for up to 3 days. The crust may soften slightly over time, but the flavors will continue to develop beautifully.

→ What type of white chocolate works best?

Choose high-quality white chocolate with at least 30% cocoa butter for the smoothest custard. Avoid white baking chips as they contain stabilizers that prevent proper melting and may result in a grainy texture.