1. Melt butter in a saucepan. Continue cooking on medium until dark brown, swirling pan occasionally. Butter will begin to smell toasty and be on the verge of burning at the bottom with little brown flecks all over.
2. Remove from heat and immediately pour into a small bowl. Chill until completely firm, at least 30 minutes in the refrigerator.
1. Put flour, powdered sugar, zest, and salt in a food processor and pulse a few times until combined. Add brown butter, cut or pinched into small pieces. Pulse a few more times, until butter is evenly distributed and pea-sized. 2. Beat egg yolk and ice water together; add to food processor and blend until just starting to form a ball. If needed, you can add another teaspoon or so of water to get the dough to come together.
3. Pour dough onto a clean counter and gently knead together with your hands.
4. Pat dough into a flattened ball, wrap with plastic, and chill at least 30 minutes before rolling out.
1. In a small stainless steel bowl, whisk together the sugar, salt, and zest until thoroughly combined and fragrant. Whisk in eggs, then citrus juices.
2. Place bowl over a pot with about 1 inch of barely simmering water. Cook over medium heat, whisking occasionally until thickened, about 8-10 minutes.
3. Remove from heat and add butter, whisking to melt and incorporate.
4. Strain mixture if needed. Chill completely.
1. Roll out tart dough to about 1/4" - 1/8" thickness on a piece of parchment or wax paper. Try to avoid adding any extra flour at this stage.
2. Cut pieces of dough slightly larger than the tart molds or ramekins you're using. Gently tuck dough into ramekins, pressing along sides. Roll over the top of the mold with the rolling pin to make smooth and even (see picture) and set aside any extra dough. Once all your ramekins are lined, chill for at least 10 minutes in the freezer until firm.
3. Meanwhile, preheat the oven to 375 F. Once tart dough is thoroughly chilled, line them with parchment paper and pie weights or beans.
4. Bake until completely cooked through and lightly golden brown, about 18-25 minutes, depending on how thin you rolled them.
5. Remove parchment and weights. Brush with beaten egg white and bake another minute or two (this helps prevent crust from getting soggy later). Cool completely.
1. Place cream in a mason jar, close the lid, and shake vigorously until soft peaks form.
2. Pour chilled curd into cooled tart shells. Pipe cream and decorate as desired.
Best served cold or at room temperature.
Keeps for 2-3 days in refrigerator, but best eaten the day they're made.
*For soft cream, feel free to whip by hand or with a mixer or hand beater. I prefer to use the “mason jar method” with amounts of whipped cream this small. Sweeten or flavor as desired.