Using a vegetable peeler, remove zest from all the tangerines, being careful to avoid the white pith. Then juice the citrus and set aside.

Put zest in the bowl of food processor. Add sugar and pulse until zest is very finely minced.

Add butter and incorporate into the tangerine sugar. Mix until light and fluffy.

Add the eggs, 1 at a time, then add tangerine juice and salt. Mix until just combined.

Pour the mixture into a 2-quart saucepan and cook over low heat until thickened, about 10 minutes, stirring constantly with a wooden spoon.

The tangerine curd will be ready when it coats a spoon. It will register about 175°F on a candy thermometer—or simply cook until thick and creamy.

Be careful not to overcook or it will curdle. Remove mixture from heat when it starts to get thick.

Transfer the curd to a small bowl. Let cool and refrigerate.

Serve with the olive oil cake and any leftover with breakfast breads, scones or shortbread.