Rhubarb White Chocolate Elderflower Tart

Spring arrived late that year, but when the first stalks of rhubarb appeared at the market, I bought far too much without a plan. A neighbor mentioned elderflower cordial she'd tucked away since summer, and suddenly I had a vision: something floral, creamy, and sharp all at once. I'd never paired white chocolate with rhubarb before, but the contrast felt right. That tart became the centerpiece of a garden lunch I'll never forget.

I served this tart to friends who swore they didn't like rhubarb. Watching them take hesitant first bites, then reach for seconds, taught me that context changes everything. The roasting mellows the rhubarb's aggression, and the custard wraps it in something almost luxurious. One friend asked if I'd used rose water. I hadn't, but the elderflower does that, it whispers instead of shouts.

Ingredients

• All-purpose flour: Forms the base of a tender, buttery crust that won't shrink if you chill it properly between steps.
• Cold unsalted butter, cubed: The secret to flaky pastry is keeping this cold, I freeze my cubes for ten minutes before starting.
• Powdered sugar: Sweetens the crust gently and gives it a finer, more delicate crumb than granulated sugar would.
• Egg yolk: Adds richness and helps bind the dough without making it tough.
• Cold water: Use sparingly, just enough to bring the dough together without making it sticky.
• White chocolate, finely chopped: Choose quality chocolate with real cocoa butter, not coating chocolate, for a custard that sets beautifully.
• Heavy cream: The backbone of the custard, providing body and a smooth mouthfeel.
• Whole milk: Lightens the custard just enough so it doesn't feel too heavy after a full meal.
• Elderflower cordial: This is the magic ingredient, floral and sweet, it ties the whole dessert together.
• Egg yolks: Thicken the custard and give it that luscious, golden color.
• Granulated sugar: Sweetens the custard and helps the rhubarb caramelize slightly during roasting.
• Vanilla extract: A subtle background note that makes the white chocolate sing.
• Rhubarb, trimmed and cut into batons: Look for firm, bright stalks, the pinker the better for visual impact.
• Lemon zest: Brightens the rhubarb and adds a citrus edge that cuts through the richness.

Instructions

Make the Tart Shell:

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

Chill and Roll:

Pat the dough into a flat disk, wrap it tightly in plastic, and let it rest in the fridge for at least thirty minutes. Roll it out on a floured surface until it's large enough to line your tart tin, then press it gently into the corners and trim the edges neatly.

Blind Bake:

Chill the lined tin for fifteen minutes, then line the pastry with parchment and fill with baking beans. Bake at 180°C for fifteen minutes, remove the beans and parchment, then bake another five to seven minutes until the base is golden and crisp.

Prepare the Custard Base:

Heat the cream and milk in a saucepan until it's steaming but not boiling. In a separate bowl, whisk the egg yolks, sugar, and vanilla until the mixture is pale and slightly thick.

Combine and Cook:

Slowly pour the hot cream into the yolk mixture, whisking constantly so the eggs don't scramble. Return everything to the saucepan and cook over low heat, stirring constantly, until the custard thickens enough to coat the back of a spoon.

Finish the Custard:

Remove from heat and stir in the chopped white chocolate and elderflower cordial until completely smooth and glossy. Pour into the cooled tart shell and refrigerate for at least an hour until firmly set.

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 fifteen minutes, then uncover and roast another five to eight minutes until tender but still holding their shape.

Assemble and Chill:

Once the rhubarb is completely cool, arrange the batons over the set custard in whatever pattern pleases you. For extra shine, brush lightly with a bit more elderflower cordial, then chill until you're ready to serve.

Pin It

The first time I brought this tart to a spring picnic, someone asked if I'd trained in pastry. I hadn't, but I'd learned to trust my instincts and taste as I went. That compliment meant more than any culinary school badge ever could. It reminded me that cooking with care and attention is its own credential.

Choosing Your Rhubarb

Look for stalks that are firm, glossy, and brightly colored, the redder the stalk, the prettier your finished tart. Avoid any that feel limp or have brown spots. Thinner stalks tend to be more tender, but thicker ones hold their shape better during roasting. I usually go for a mix, cutting the thicker pieces lengthwise so everything cooks evenly.

Making It Ahead

This tart is a dream for entertaining because you can make every component a day in advance. The tart shell keeps beautifully in an airtight container, the custard stays silky in the fridge, and roasted rhubarb only gets better as it sits. Assemble the tart the morning of your gathering, and you'll have one less thing to worry about. Just keep it chilled until the last possible moment.

Serving Suggestions and Variations

I love serving this tart with a small dollop of lightly whipped cream or crème fraîche on the side. A sprinkle of toasted pistachios or sliced almonds adds a lovely crunch and a pop of color. If rhubarb isn't in season, try roasted strawberries or poached plums, just adjust the sugar to taste.

• Pair with a chilled glass of Moscato, Prosecco, or an elderflower spritz for a truly elegant finish.
• Dust the edges with a tiny bit of powdered sugar right before serving for a bakery-worthy presentation.
• Leftovers keep well for up to two days in the fridge, covered loosely with plastic wrap.

Pin It

Every time I make this tart, I'm reminded that the best recipes aren't just about following steps, they're about paying attention and adjusting as you go. Trust yourself, taste everything, and don't be afraid to make it your own.

Recipe FAQs

→ Can I prepare this tart in advance?

Yes, this is an excellent make-ahead dessert. You can prepare the tart shell and custard filling up to 2 days in advance. Roast the rhubarb the day before and assemble just before serving for the best presentation and texture.

→ What can I substitute for elderflower cordial?

If elderflower cordial is unavailable, try rose water, orange blossom water, or a light honey syrup. You could also use a splash of limoncello or simply omit it and increase the vanilla extract for a more classic flavor profile.

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

Blind baking the crust until golden is essential. Make sure it's completely cooled before adding the custard. You can also brush the baked shell with a thin layer of melted white chocolate as a moisture barrier before filling.

→ Can I use frozen rhubarb instead of fresh?

Fresh rhubarb works best for roasting as it holds its shape better. If using frozen, thaw completely and pat dry to remove excess moisture. You may need to reduce roasting time slightly to prevent the rhubarb from becoming too soft.

→ What other fruits pair well with white chocolate custard?

Strawberries, raspberries, and poached pears all complement white chocolate beautifully. Blood oranges or passion fruit also create stunning flavor combinations. Choose fruits that provide a pleasant tartness to balance the sweetness.

→ How long will the tart keep in the refrigerator?

The assembled tart will keep for up to 2 days when stored covered in the refrigerator. However, the crust may soften slightly over time, so it's best enjoyed within 24 hours for optimal texture and freshness.