Fruit curds, of which lemon curd is a prime example, are a sort of fruit custard, but made without milk or cream. To make lemon curd, a mixture of lemon juice, zest, sugar, eggs, and butter is gently cooked until thick. When cooled, the curd is thick enough to spread. Rich and luscious with the bright tang of lemon, lemon curd is a classic topping for toast or scones, but it is much more versatile than that. Baked in a sweet tart shell it makes an incredible lemon tart, which can be topped with meringue. It can also serve as a filling for cookies, cakes, and pastries (I love Meyer lemon éclairs), or it can be swirled into just-churned French vanilla ice cream. Lemons are the classic fruit used to make curd, but they are by no means the only one. Any citrus fruit can be used—limes, oranges, grapefruit, tangerines, and so on—as well as purées of berries such as raspberries or blackberries. Mix the zest and juice (in citrus curds, the zest plays as large a part in the flavor as the juice) or berry purée with sugar and eggs and butter, and cook the mixture the same way as an egg custard: in a heavy-bottomed pot, stirring constantly, over medium heat, until it coats the back of a spoon. Take care not to boil the mixture or the eggs will curdle. Pour into a bowl or glass jars to cool. The curd will continue to thicken as it cools. Store, refrigerated, in a tightly sealed container for up to 2 weeks.

　　

Ingredients

makes 2 cups

　　4 lemons

　　2 eggs

　　3 egg yolks

　　2 tablespoons milk

　　1/3 cup sugar

　　1/4 teaspoon salt (omit if using salted butter)

　　6 tablespoons butter, cut into small pieces

　　

Step 1

Wash and dry: 4 lemons.

　　

Step 2

Grate the zest of one of the lemons on the small holes of a grater. Juice the lemons; there should be about 1/2 cup juice. Beat until just mixed: 2 eggs, 3 egg yolks, 2 tablespoons milk, 1/3 cup sugar, 1/4 teaspoon salt (omit if using salted butter).

　　

Step 3

Stir in the lemon juice and zest and add: 6 tablespoons butter, cut into small pieces.

　　

Step 4

Cook the mixture in a small nonreactive heavy pan, stirring constantly, over medium heat until it is thick enough to coat a spoon. Do not boil or the eggs will curdle. When thick, pour into a bowl or glass jars to cool. Cover and refrigerate.

　　

Variations

Step 5

With their sweeter juice and perfumed peel, Meyer lemons make an especially good curd. Make the recipe with the juice of 1 regular lemon and 3 Meyer lemons and the grated zest of 2 Meyer lemons.

　　

Step 6

To make a frosting, fold lightly sweetened whipped cream into lemon curd. I usually use equal parts of whipped cream and curd.

　　

Step 7

To make a lemon curd tart, prebake an 9-inch Sweet Tart Dough shell (page 183) and fill with 2 cups lemon curd. Smooth out the curd and bake in a preheated 375°F oven for 15 to 20 minutes or until the lemon curd is set.

　　The Art of Simple Food