Rhubarb White Chocolate Elderflower Tart

The scent of elderflower always takes me straight back to a Sunday afternoon when I had too many ingredients and not enough plan. I'd bought rhubarb on impulse at the market, spotted a bottle of elderflower cordial gathering dust in the pantry, and somehow decided white chocolate belonged in the mix. What started as a wild experiment turned into this tart, a dessert that looks far more elegant than the chaos that birthed it. Now it's my go-to when I want to look like I have my life together.

I first served this tart at a birthday dinner where half the guests were late and the other half were already on their second glass of wine. By the time dessert arrived, everyone had forgotten about the delayed main course. Someone actually asked if I'd ordered it from a patisserie, which I took as the highest compliment even though I'd nearly overbaked the crust earlier that day. The rhubarb glistened under the kitchen light, and for a moment, I felt like a real pastry chef.

Ingredients

• All-purpose flour: Forms the base of your tart shell, keep it cold and don't overwork it or you'll end up with a tough crust instead of a tender one.
• Cold unsalted butter: The secret to flaky pastry is butter straight from the fridge, cubed small so it stays solid until it hits the oven.
• Powdered sugar: Sweetens the crust gently and helps create that melt-in-your-mouth texture you want in a tart shell.
• Egg yolk: Binds the dough together and adds richness, save the white for an omelette tomorrow.
• White chocolate: Choose good quality with real cocoa butter, not the candy aisle stuff, because it melts into the custard and defines the whole filling.
• Heavy cream and whole milk: The duo that makes the custard luxurious without being too heavy, you need both for the right balance.
• Elderflower cordial: This is where the magic happens, it brings a delicate floral note that makes people ask what that lovely flavor is.
• Egg yolks: They thicken the custard into something silky and rich, just stir constantly so they don't scramble on you.
• Rhubarb: Look for firm stalks with good color, they'll roast into tender batons that hold their shape and add that essential tartness.
• Lemon zest: Brightens the rhubarb and keeps it from tasting flat, always zest before you juice.

Instructions

Mix the Tart Dough:

Pulse the flour, cold butter cubes, powdered sugar, and a pinch of salt in your food processor until it looks like coarse sand. Add the egg yolk and a tablespoon of cold water, pulsing just until the dough starts to clump together, if it's still too dry, add a tiny splash more water.

Chill and Roll:

Pat the dough into a flat disk, wrap it in plastic, and let it rest in the fridge for 30 minutes so the gluten relaxes. Roll it out on a floured counter until it's big enough to line your tart tin, then press it in gently, trim the edges, and chill again for 15 minutes.

Blind Bake the Shell:

Heat your oven to 180°C, line the chilled crust with parchment, and fill it with baking beans to keep it from puffing up. Bake for 15 minutes, then remove the beans and parchment and bake another 5 to 7 minutes until it's golden and crisp.

Prepare the Custard Base:

Warm the cream and milk in a saucepan until steaming, then whisk your egg yolks with sugar and vanilla until they're pale and thick. Slowly pour the hot cream into the yolks while whisking constantly so they don't curdle.

Cook and Finish the Custard:

Pour the mixture back into the saucepan and cook over low heat, stirring constantly until it coats the back of a spoon. Take it off the heat, stir in the chopped white chocolate and elderflower cordial until glossy and smooth, then pour it into your cooled tart shell and chill for at least an hour.

Roast the Rhubarb:

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

Assemble and Chill:

Once the rhubarb has cooled completely, arrange it artfully over the set custard. If you want extra shine, brush the rhubarb lightly with a bit more elderflower cordial, then chill the whole tart until you're ready to serve.

Pin it

There's a moment when you pull this tart from the fridge and see the pink rhubarb against the pale custard that makes all the steps worth it. I once brought it to a potluck where someone admitted they usually hate rhubarb, but they had two slices anyway. It's become my proof that a little effort and some floral notes can turn skeptics into believers, and that's a kind of magic I'll take any day.

Make-Ahead Tips

The beauty of this tart is that every element can be prepped in advance. Bake the tart shell up to two days ahead and store it in an airtight container at room temperature. The custard filling can be made and poured into the shell a day before serving, just keep it covered in the fridge. Roast the rhubarb the morning of or even the night before, and assemble everything a few hours before guests arrive so the flavors have time to meld.

Serving Suggestions

This tart shines on its own, but a small dollop of lightly whipped cream or a scoop of vanilla ice cream never hurt anyone. I love serving it with a chilled glass of Moscato or a homemade elderflower spritz, the floral notes echo beautifully. For texture, scatter toasted pistachios or sliced almonds over the top just before serving, they add a gentle crunch that contrasts with the creamy custard.

Variations and Swaps

If rhubarb isn't in season or you're not a fan, swap in fresh strawberries or raspberries for a sweeter, softer topping. You can replace the elderflower cordial with a splash of limoncello or even a bit of rose water if you want a different floral note. For a gluten-free version, use a good quality gluten-free flour blend in the crust, just expect a slightly different texture.

• Try adding a handful of finely chopped pistachios to the tart dough for a nutty twist.
• Swap white chocolate for dark chocolate and skip the elderflower for a richer, less floral custard.
• Use blood orange zest instead of lemon with the rhubarb for a deeper citrus flavor.

Pin it

This tart has become my answer to spring, to celebrations, and to moments when I want to feel accomplished in the kitchen. It's a little bit fancy, a little bit forgiving, and always worth the effort.

Recipe FAQs

→ Can I make this tart ahead of time?

Yes, this tart is perfect for making ahead. You can prepare the crust and custard filling up to 24 hours in advance. Roast the rhubarb on the day of serving for best texture and color, or prepare it a few hours ahead and keep refrigerated.

→ What can I substitute for elderflower cordial?

If elderflower cordial is unavailable, try a light honey syrup, rose water, or orange blossom water for floral notes. You can also use a squeeze of lemon juice with a tablespoon of sugar for a simpler citrus flavor.

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

Blind baking the crust thoroughly until golden ensures a crisp base. Make sure the crust is completely cooled before adding the custard filling, and allow the custard to set properly in the refrigerator before topping with rhubarb.

→ Can I use frozen rhubarb instead of fresh?

Fresh rhubarb is recommended for best texture and presentation. Frozen rhubarb tends to be softer and releases more liquid when roasted, which can make the topping watery. If using frozen, thaw and drain thoroughly before roasting.

→ How should I store leftover tart?

Store the tart covered in the refrigerator for up to 2 days. The crust may soften slightly over time, so it's best enjoyed within 24 hours for optimal texture. Bring to cool room temperature before serving for best flavor.

→ What type of white chocolate works best?

Use good-quality white chocolate with at least 30% cocoa butter for a smooth, creamy custard. Avoid white chocolate chips or coating chocolate, as they contain stabilizers that prevent proper melting and can result in a grainy texture.