1-Step 1: Set up your double boiler Fill the bottom of a double boiler with 1 to 2 inches of water and bring it to a simmer over high heat. Then reduce the heat to low so the water stays gently steaming, not boiling hard. If you do not have a double boiler, place a heatproof bowl over a saucepan of simmering water.

2-Step 2: Mix the base ingredients In the top pan or heatproof bowl, combine the 4 large egg yolks, 2/3 cup granulated sugar, 1 tablespoon lemon zest, 1/3 cup fresh lemon juice, and 1/8 teaspoon salt. Whisk until the mixture looks smooth and slightly pale. Fresh juice is important here because bottled juice can taste flat and a little bitter.

3-Step 3: Cook slowly and whisk constantly Place the bowl over the simmering water and whisk constantly. Keep the heat gentle so the eggs thicken slowly instead of curdling. After about 10 minutes, the mixture should turn thick and glossy, almost like hollandaise sauce. It should coat the back of a spoon and reach about 170°F.

4-Step 4: Add the butter Remove the curd from the heat and whisk in the 6 tablespoons unsalted butter, one piece at a time. Let each piece melt before adding the next. This step gives the curd its silky finish and rich flavor.

5-Step 5: Strain and chill Pour the curd into a jar or bowl. If you want an extra-smooth texture, strain it through a fine mesh sieve first. Cover the surface directly with plastic wrap so a skin does not form, then refrigerate until fully set.

6-Step 6: Serve and enjoy Once chilled, your lemon curd recipe is ready to spread, spoon, or swirl. It is wonderful on breakfast breads, folded into yogurt, or used as a filling for cakes and pastries. If you are making brunch for a crowd, it also pairs nicely with croissant bread or a tray of raspberry muffins.