Rhubarb White Chocolate Elderflower Tart

The smell of elderflower blooming outside my kitchen window is what made me think of this tart in the first place. I was flipping through a baking book, and the idea of pairing white chocolate with rhubarb seemed risky, maybe even strange. But something about the floral sweetness against that sharp, tangy rhubarb felt right. I made it on a whim for a dinner party, and by the time dessert came around, the table went quiet in that way that only happens when something tastes unexpectedly beautiful.

I once brought this to a spring brunch where half the guests claimed they didnt like rhubarb. By the end of the meal, three people had asked for the recipe. One friend told me she never knew rhubarb could taste this good, and I realized it was the roasting that did it, coaxing out sweetness instead of just sour. That tart became my go to whenever I wanted to prove that simple ingredients, treated with a little care, can completely change someones mind.

Ingredients

• All-purpose flour: The foundation of a tender, flaky crust that holds up under creamy custard without going soggy.
• Cold unsalted butter, cubed: Keep it cold so it creates those delicate, buttery layers when it hits the oven.
• Powdered sugar: Sweetens the dough gently and helps it stay tender instead of tough.
• Egg yolk: Adds richness and binds the dough without making it heavy.
• Cold water: Just enough to bring everything together, use sparingly so the crust stays crisp.
• Pinch of salt: Balances sweetness and sharpens all the other flavors.
• White chocolate, finely chopped: Choose good quality with real cocoa butter, it melts smoothly and gives the custard a silky texture.
• Heavy cream: Creates that luxurious, creamy filling that sets beautifully in the fridge.
• Whole milk: Thins the custard just enough so its pourable and not too dense.
• Elderflower cordial: The secret ingredient that makes this tart taste like springtime in a glass.
• Egg yolks: Thicken the custard and give it that classic golden richness.
• Granulated sugar: Sweetens the custard and the rhubarb without overpowering their natural flavors.
• Vanilla extract: A warm background note that ties everything together.
• Rhubarb, trimmed and cut into 5 cm batons: Roasting transforms it from mouth puckeringly tart to tender and sweet with just enough tang.
• Lemon zest: Brightens the rhubarb and adds a fresh citrus note that cuts through the richness.

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 water until the dough just starts to clump together. Shape it into a disk, wrap it up, and let it chill for 30 minutes so it rolls out without shrinking later.

Roll and Blind Bake:

Roll the chilled dough out on a floured surface, press it gently into your tart tin, trim the edges, and chill again for 15 minutes. Line it with parchment and baking beans, bake at 180°C for 15 minutes, then remove the beans and bake another 5 to 7 minutes until golden and crisp.

Make the Custard Filling:

Heat the cream and milk until steaming, then slowly whisk it into the egg yolks and sugar to temper them without scrambling. Return the mixture to the pan, stir gently over low heat until it thickens enough to coat the back of a spoon, then stir in the white chocolate and elderflower cordial until smooth.

Fill and Chill:

Pour the warm custard into your cooled tart shell and pop it in the fridge for at least an hour until its completely set. This is the step that lets the flavors meld and the texture turn silky.

Roast the Rhubarb:

Lay the rhubarb batons in a single layer in a baking dish, sprinkle with sugar and lemon zest, drizzle with elderflower cordial, and cover with foil. Roast at 190°C for 15 minutes, then uncover and roast another 5 to 8 minutes until tender but still holding its shape.

Assemble the Tart:

Arrange the cooled rhubarb over the set custard in whatever pattern makes you happy. If you want a glossy finish, brush a little extra elderflower cordial over the top before serving.

Pin it

I served this tart at my sisters garden party last May, and it sat on the table like a centerpiece before anyone even touched it. The pink rhubarb against the pale custard looked almost too pretty to eat. But once we sliced into it, the conversation shifted from how beautiful it was to how incredible it tasted, and I watched as people went back for second slivers, trying to be polite but clearly wanting more.

Choosing the Right Rhubarb

Look for stalks that are firm and brightly colored, either deep red or vibrant pink. Thinner stalks tend to be more tender and less fibrous, which means they roast beautifully without turning stringy. If your rhubarb is very thick, you can slice the batons lengthwise so they cook evenly. Never use the leaves, theyre toxic, just trim them off and compost them.

Making It Ahead

This tart actually improves when made a day in advance because the flavors have time to settle and deepen. You can bake the crust, make the custard, and roast the rhubarb all separately, then assemble everything the morning of your event. Just keep the components covered in the fridge, and dont top the tart with rhubarb until a few hours before serving so it stays looking fresh.

Serving and Storing

Serve this tart cold or at cool room temperature with a dollop of lightly whipped cream or a scoop of vanilla ice cream if you want to go all out. Leftovers keep well in the fridge for up to three days, covered loosely with plastic wrap. The crust may soften slightly after the first day, but the flavor stays just as lovely.

• For a nutty crunch, scatter toasted pistachios or slivered almonds over the top just before serving.
• If rhubarb isnt in season, try roasted strawberries or poached apricots for a different but equally delicious finish.
• Pair it with a chilled glass of Moscato or an elderflower spritz to echo the floral notes in the custard.

Pin it

This tart has a way of making ordinary afternoons feel special, like youve put real thought and care into something beautiful. I hope it brings as much quiet joy to your table as it has to mine.

Recipe FAQs

→ Can I make this tart ahead of time?

Yes, this tart is perfect for making ahead. The custard-filled tart shell can be prepared up to 24 hours in advance and stored in the refrigerator. Add the roasted rhubarb just a few hours before serving for the best presentation and texture.

→ What can I substitute for elderflower cordial?

If elderflower cordial is unavailable, you can use a mixture of lemon juice and honey, or substitute with rose water for a different floral note. Alternatively, use vanilla extract and increase the sugar slightly to maintain sweetness.

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

Blind baking the crust until fully golden and allowing it to cool completely before adding the custard helps create a moisture barrier. You can also brush the baked crust lightly with beaten egg white and return it to the oven for 2 minutes to seal.

→ Can I use frozen rhubarb instead of fresh?

Yes, frozen rhubarb can work, but thaw and drain it thoroughly first to remove excess moisture. Pat dry with paper towels before roasting. Fresh rhubarb will give better texture and appearance, but frozen is a convenient alternative.

→ What's the best way to slice this tart cleanly?

Use a sharp knife dipped in hot water and wiped dry between cuts. The chilled custard should be firm enough to slice neatly. Allow the tart to sit at room temperature for 10-15 minutes before slicing for easier cutting.

→ 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 rhubarb may soften slightly over time, but the flavor remains delicious. Bring to room temperature for 15 minutes before serving.