From Citrus Recipes by Curtis and Esin Decarion, Café Esin
6-7 gingersnap cookies
2 tablespoons melted butter
Crush cookies in a food processor until fine. Stir in melted butter. Press mixture into bottom and sides of 9-inch tart pan. Bake at 325 degrees for 10 to 12 minutes. Set aside.
2 egg yolks
1/2 cup Meyer lemon juice
3/4 cup granulated sugar
5 ounces cold unsalted butter, cut into 1/2 inch cubes
Zest of 2 Meyer lemons
Whisk together eggs and egg yolks in a stainless steel bowl. Add lemon juice and sugar, stirring until smooth. Place the bowl over a pan of simmering water and cook, whisking constantly until it thickens. Remove from heat and immediately submerge the bowl in an ice water bath just enough to cool the outside of the bowl-about 10 seconds. Remove from the ice bath. Add butter piece by piece. Add lemon zest and stir lightly to combine. Pour the lemon filling into prepared tart pan. Bake about 10 minutes until filling has set. Take it out of the oven and let it cool.
½ cup egg whites (about 4), warm
1 cup sugar
½ teaspoon cream of tartar
Place egg whites in mixing bowl. Place the bowl in a warm water bath to heat the bowl. With the whisk attachment, beat egg whites and cream of tartar on medium speed until soft peaks begin to form. Raise speed to high and gradually add the sugar. Beat the mixture until stiff and glossy peaks form. Spread the meringue over the tart, covering to the edges. Create peaks the meringue while spreading it by pulling up with the spatula. Form enough points to cover entire tart. Use a kitchen blow torch to brown the meringue all over.