Heat half-and-half in a double boiler over medium heat. In a medium bowl, whisk together sugar and egg yolks until yolks turn thick and pale. Temper yolks by gradually adding the hot half-and-half mixture a cup at a time while whisking vigorously so as not to cook the eggs. Return mixture to the double boiler and whisk over simmering water until slightly thickened and heated through, 10-15 minutes. Dilute tapioca starch with remaining 2 tablespoons half-and-half and add to mixture. Continue whisking to a custard consistency that coats the back of a spoon, about 2 minutes. Transfer custard to a heatproof bowl and whisk in azuki bean paste. Set over an ice bath and refrigerate overnight (or at least 12 hours). Pour custard into an ice cream maker and process the custard according to manufacturer's instructions, 30 to 35 minutes. Transfer to an airtight container and freeze. Makes 10 servings.
Approximate Nutrient Analysis per serving:
290 calories, 13 g fat, 8 g saturated fat, 110 mg cholesterol, 50 mg sodium, 38 g carbohydrate, 2 g fiber, 10 g sugar, 7 g protein