Candied Kumquat and Ricotta Tart

Thinly slice kumquats crosswise with a sharp knife, discarding seeds.

Bring water and 2 cups sugar to a boil in a 2-quart heavy saucepan, stirring until sugar is dissolved, then simmer syrup, uncovered, 5 minutes. Stir in kumquats and simmer gently 10 minutes.

Drain and cool kumquats in a sieve set over a bowl, then return drained syrup to pan and boil until reduced to about 11/3 cups, 3 to 5 minutes.

Finely grind fennel seeds in coffee/spice grinder, then transfer to a bowl and whisk together with ricotta, remaining 2 tablespoons sugar, and a pinch of salt just until ricotta is slightly smoother.

Whisk in sour cream until just combined and spread evenly over bottom of tart shell.

Arrange kumquats as evenly as possible over ricotta using your fingers or a small spoon, separating slices as necessary with a skewer, then brush kumquats with some of reduced syrup.

Remove side of tart pan.

• Kumquats can be candied 1 day ahead and chilled in syrup (before reducing), covered. Warm mixture before proceeding. • Ricotta filling can be made 1 day ahead and chilled, covered. • Tart can be assembled 2 hours ahead and kept at room temperature.