In a medium saucepan, whisk together the 1/2 cup sugar and cornstarch. Slowly whisk in the milk until combined. Place pan over medium heat and cook, whisking constantly, until mixture thickens and begins to bubble. Remove from heat and stir in heavy cream, vanilla extract, and salt.
Place chopped kumquats in a medium bowl. Sprinkle with 3 tablespoons sugar and stir to combine. Let sit for 10 minutes.
Transfer kumquat mixture to a blender and blend until smooth. Add blended kumquat mixture to the custard base and stir to combine.
Pour mixture into an ice cream maker and freeze according to manufacturer’s instructions.
Transfer ice cream to an airtight container and freeze for at least 4 hours before serving.
Interesting Facts
Kumquats are believed to have originated in China.
Kumquats are a citrus fruit that have a sweet skin and tart flesh.
Kumquat ice cream is the perfect combination of sweet and tart.