Save Pin My neighbor handed me a bundle of rhubarb stalks over the fence one Saturday morning, their ruby edges catching the light. I had white chocolate left from another project and a bottle of elderflower cordial I'd been hoarding since summer. The tart came together almost by accident, but the combination of floral sweetness against sharp rhubarb felt like capturing spring in pastry. Now it's the dessert I make when I want to impress without announcing it.
I brought this tart to a spring potluck where everyone else showed up with store-bought pies. The first slice revealed that pale custard against the bright pink rhubarb, and suddenly I had a crowd around my corner of the table. Someone asked if I went to pastry school. I didn't, but I've learned that a beautiful tart buys you a lot of credibility.
Ingredients
- All-purpose flour: Forms the base of your crust and should be measured by spooning into the cup, not scooping, to avoid a tough shell.
- Cold unsalted butter: Keep it properly cold so it creates flaky layers instead of melting into the dough before baking.
- Powdered sugar: Dissolves faster than granulated and gives the crust a more tender, melt-in-your-mouth texture.
- Egg yolk: Adds richness and helps bind the dough without making it chewy like a whole egg would.
- White chocolate: Choose a good quality brand with cocoa butter listed first for a smoother, creamier custard.
- Heavy cream: The fat content is essential for a custard that sets but still feels luxurious on the tongue.
- Elderflower cordial: Brings a delicate floral sweetness that complements both the white chocolate and the tart rhubarb perfectly.
- Rhubarb: Look for firm stalks with vibrant color and trim away any leaves, which are toxic even in small amounts.
- Lemon zest: Brightens the rhubarb and keeps the sweetness from becoming flat or one-dimensional.
Instructions
- Prepare the Tart Crust:
- Pulse the flour, cold butter, powdered sugar, and salt in your food processor until it looks like coarse sand with some pea-sized bits still visible. Add the egg yolk and cold water gradually, pulsing just until the dough clumps together when you pinch it.
- Chill and Roll:
- Press the dough into a flat disk, wrap it tightly, and refrigerate for 30 minutes so the gluten can relax. Roll it out on a floured counter to about 3 mm thick, then drape it over your tart tin and press it gently into the corners without stretching.
- Blind Bake:
- Line the chilled crust with parchment and fill it with baking beans to prevent puffing during the first bake. After 15 minutes, remove the beans and parchment, then bake until the bottom is golden and no longer looks wet.
- Make the Custard Filling:
- Heat the cream and milk until you see steam rising but no bubbles forming along the edge. Whisk your egg yolks with sugar and vanilla until the mixture turns pale and slightly thick, then temper by pouring the hot cream in slowly while whisking constantly to avoid scrambling.
- Thicken and Combine:
- Return the mixture to low heat and stir with a wooden spoon until it coats the back and holds a line when you drag your finger through it. Remove from heat, add the white chocolate and elderflower cordial, and stir until completely smooth and glossy.
- Roast the Rhubarb:
- Lay the rhubarb pieces in a single layer so they cook evenly, then sprinkle with sugar, lemon zest, and elderflower cordial before covering with foil. Roast covered first to soften, then uncover to caramelize the edges slightly without turning them to mush.
- Assemble the Tart:
- Pour the custard into your cooled tart shell and refrigerate until firm to the touch, at least an hour. Arrange the cooled rhubarb pieces on top just before serving so they stay vibrant and the custard stays set.
Save Pin The first time I served this, my friend who claims to hate rhubarb ate two slices and asked for the recipe. She said the elderflower made it taste like something she'd order at a fancy cafe. I didn't tell her how simple it actually was.
Make-Ahead Magic
The tart shell can be baked two days in advance and kept covered at room temperature. The custard filling stays silky for up to a day in the fridge once set, and the roasted rhubarb holds beautifully overnight in a sealed container. Just assemble the components a few hours before serving so the rhubarb doesn't weep into the custard.
Choosing Your Rhubarb
Field rhubarb with deep red stalks looks stunning, but the paler hothouse variety works just as well and sometimes tastes a bit sweeter. Avoid any stalks that feel limp or have brown spots, and always choose pieces that are firm enough to snap cleanly when you bend them. Thicker stalks can be halved lengthwise so they roast evenly with the thinner ones.
Serving and Storage
This tart slices best when fully chilled, so use a sharp knife wiped clean between cuts for neat edges. It keeps covered in the fridge for up to three days, though the rhubarb may release a little juice as it sits. A dollop of lightly whipped cream or a handful of toasted pistachios adds a nice contrast without overwhelming the delicate flavors.
- Serve chilled or at cool room temperature for the best texture and flavor balance.
- Leftovers can be covered loosely with plastic wrap to avoid condensation on the surface.
- If the rhubarb looks dull after a day, a light brush of elderflower cordial brings back the shine.
Save Pin There's something quietly impressive about setting down a tart this pretty and watching people realize it tastes even better than it looks. It's become my go-to when I want to celebrate spring without spending all day in the kitchen.
Recipe FAQs
- → Can I make this tart ahead of time?
Yes, this is an excellent make-ahead dessert. The tart shell and custard can be prepared up to 2 days in advance. Roast the rhubarb the day before and assemble within a few hours of serving for the best presentation and texture.
- → What can I substitute for elderflower cordial?
If elderflower cordial is unavailable, use a light floral syrup like rose or lavender, or substitute with a mixture of honey and lemon juice for sweetness without the floral notes. Adjust to taste as elderflower has a distinctive flavor.
- → How do I prevent the rhubarb from becoming mushy?
Keep a close eye during roasting and remove when the rhubarb is tender but still holds its shape. Covering with foil initially helps it cook evenly, while the final uncovered roasting caramelizes without overcooking. Cool completely before arranging on the tart.
- → Can I use frozen rhubarb instead of fresh?
Fresh rhubarb is recommended for better texture and presentation. Frozen rhubarb releases more liquid and may become too soft when roasted. If using frozen, thaw completely, drain well, and reduce roasting time slightly.
- → What type of white chocolate works best?
Choose high-quality white chocolate with at least 30% cocoa butter for the smoothest custard. Avoid white chocolate chips as they contain stabilizers that prevent proper melting. Finely chop the chocolate for even incorporation into the warm custard.
- → How should I store leftovers?
Cover the tart loosely with plastic wrap and refrigerate for up to 3 days. The rhubarb may release some juice over time, so it's best enjoyed within 24 hours of assembly. Bring to cool room temperature before serving for optimal flavor.