Every week, FOOD52's Senior Editor Kristen Miglore is unearthing recipes that are nothing short of genius.
Today: What butter can do for curd when it comes in at a different cue. Meet your new tart filling, scone spread, and trifle layer -- and the best lemon pudding you'll ever taste.

- Kristen
We've already seen lemon do some miraculous things on FOOD52 (Posset. Lazy tarts. Sorbet. Sponge cups.). And we've witnessed the magic of emulsification.
Now we get to talk about them together. With butter. I'm so happy right now.

FOOD52er sarabclever taught me about this delightful substance, a lemon cream that comes from the legendary Tartine Bakery in San Francisco and its namesake cookbook. (Sara went ahead and did this with it too.)
Tartine's recipe takes the traditional lemon curd process and reverses it, not only saving time, but also producing something richer, silkier, and just better in the end.



A typical lemon curd starts with lemon juice, egg (yolks or a mix), sugar, and sometimes butter melted together and whisked over a double boiler until it thickens. It's delicious. Lemon meringue pie, pavlova, and trifle have been known to depend on it.
But Elisabeth Prueitt, Tartine Bakery's pastry chef and co-owner, holds off on adding the butter till after the other ingredients have gotten to know one another. And then she adds a lot of it, violently -- a technique inspired by Pierre Hermé. You'll see!

Naturally (this is an iconic pastry book, after all), there are specific temperatures involved, but I've made this with scalawag thermometers that couldn't be trusted, and just went by looks. It's very forgiving.
You just do that whisking-over-a-double boiler thing till it gets thick and glassy and leaves a lingering trail behind your whisk (or you can go rogue and cook it over low, direct heat -- just be prepared to strain out any cooked egg bits).
Then you pull it off the heat to cool while you slice your butter into neat tablespoons and pull out your blender.



Here comes the violence: You scrape the curd into the blender and let it rip, dropping in pats of butter one at a time. Each one is greeted with a satisfying -- suck! glurgle! -- as the lemon curd drinks up the butter and slowly swells.
The chunks of chilled butter cool down the mixture and thicken it faster than the traditional all-stovetop method would, while the blades of the blender beat in extra air.

The result is a buoyant, stable buttercream that stays spreadable in the fridge for days. It's smoother and more mellow than curd, which is often so severe in its pucker that you must take measures to lighten it after the fact -- a mousse folded in; a thick, sweet layer of meringue piled on top. You won't need, or want, to do that here.
You will, however, sweep it onto your scones or toast, lard it through the middle of a layer cake, or smooth it into a tart crust. (Please consider garnishing with Tartine's mohawk-esque dollops of cream and flower petals if you do.)

And I will go down fighting if anyone tells me I can't eat this as a pudding.
Tartine Bakery's Lemon Cream
Note: If you're looking for a genius tart shell to stick this in, try Paule Caillat's Brown Butter Tart Crust.
Adapted very slightly from Tartine by Elisabeth Prueitt and Chad Robertson (Chronicle, 2006)
Serves 4
1/2 cup + 2 tablespoons lemon juice
3 large eggs
1 large egg yolk
3/4 cup sugar
Pinch of salt
1 cup unsalted butter
See a slideshow and the full recipe (and save and print it) here.

Got a genius recipe to share -- from a classic cookbook, an online source, or anywhere, really? Please send it my way (and tell me what's so smart about it) at kristen@food52.com.
Photos by James Ransom
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