1-Preparing the Blueberry Sauce: First, combine the fresh blueberries, white granulated sugar, cardamom (if using), and water in a wide shallow pan. Heat over medium heat, simmering until the blueberries soften and begin to burst, which takes about 5 minutes. As the blueberries cook, gently mash them with a potato masher to release their juices.

2-Preparing the Blueberry Sauce: Continue cooking until the mixture thickens to a sauce-like consistency, about 5 to 10 minutes. Be sure to scrape the bottom and sides of the pan while cooking to avoid sticking and burning. Once thickened, allow the mixture to cool for about 15 minutes.

3-Creating the Ice Cream Base: In a large bowl, measure out the cold whole milk and heavy cream, then stir in the cooled blueberry sauce. It’s normal for separation to occur at this stage, so don’t be alarmed. Refrigerate the mixture for at least 1 hour to chill it completely.

4-Churning and Freezing: When the mixture is thoroughly chilled, process it in an ice cream maker according to the manufacturer’s instructions until it reaches a soft serve consistency. Be careful not to fill the ice cream maker more than two-thirds full to allow for expansion during churning. If you have excess mixture, you can process it in batches or store it in the refrigerator for up to two days (just stir if separation occurs).

5-Churning and Freezing: Once churning is complete, transfer the ice cream to a freezer-safe container. A metal bread pan works particularly well due to better cold conduction, which speeds up the freezing process. Freeze until firm, which takes about 8 hours.