Split and scrape vanilla bean: On cutting board, slit the bean lengthwise. Scrape down the length of the bean to scoop out all the seeds. Place the seeds in a little mound on the cutting board. Add a teaspoon of granulated sugar; work the sugar and seeds together with the tip of your middle finger, until sugar and seeds are totally mixed and seeds don't stick together anymore.
Place vanilla bean and seeds, sugar, and milk in a saucepan. Stir occasionally until the mixture just starts to come to a boil. Cover; remove from heat and let stand 30 minutes.
Remove vanilla bean and scrape it between your thumb and forefinger to get every bit of seed and pulp out of it. Discard pod.
Cool overnight. Add to ice cream freezer and freeze according to manufacturer's directions.