Combine all ingredients in a 2-quart saucepan.

Whisk constantly over medium-low heat until thickened and the first bubbles reach the surface, about 5–6 minutes. Judge the thickening rather than the clock; keep whisking around the pan's edges.

Remove from heat. If needed, pass through a fine-mesh strainer for a smoother texture.

Transfer to a clean bowl and press food-safe plastic wrap against the surface to prevent a skin.

Cool briefly, then refrigerate until chilled and set. It thickens as it cools.

Spread the chilled curd on toast or scones, or use as a dessert filling. Keep refrigerated.