WHISK the heavy cream, milk, half the sugar, and vanilla bean seeds and pod in a sauce pan and bring to a simmer. (Note: If your vanilla beans are dried out, microwave 10 seconds at 50% power to plump up before splitting.)
COVER and allow the vanilla bean seeds and pod to steep in the hot cream for 1 hour.
WHISK the egg yolks and other half of the sugar just enough to liquefy and smooth out; whisk cooled cream into the yolks.
STRAIN the custard through a chinois or a fine mesh strainer and skim off any foam. Bake immediately or chill in the refrigerator overnight, or until needed. The custard will keep 2 or 3 days in the refrigerator.
ARRANGE brûlée dishes on a parchment-lined sheet pan next to the stove when ready to bake. Filling the dishes next to the stove or on top of the stove saves spills; it's hard to carry a tray of liquid-filled dishes acrosss the kitchen without spilling.
DISTRIBUTE the blueberries evenly in the dishes, 30 grams (1 ounce) per dish.
POUR custard mixture into dishes using a four-cup measuring cup with a spout: 120 grams (1/2 cup) per dish. Make sure that all blueberries are evenly distributed and submerged in the liquid. Use a torch to dissolve any bubbles or foam on top.
BAKE at 225°F (107°C), approximately 1 hour. Watch very closely towards the end of baking. The custards should be set and not "jiggly" in center when you gently shake the pan. Remove from the oven while they are still very smooth and shiny, and in bakeshop-speak, before they start to soufflé (bubble up) around the edges. You want very smooth tops.
COOL to room temperature and then refrigerate the custards several hours or overnight.
WAIT until just before servig to brûlée the tops.
BRÛLÉE THE TOPS: If the custards have condensation on top, blot dry with a paper towel before spreading on sugar. Place 1 1/2 tablespoons of superfine sugar in the center of a dish of cold custard. Using the back of a teaspoon, spread the sugar gently to the edges in an even layer, without splashing sugar on the rim of the dish. Just in case, clean edges of the dishes with a damp paper towel. Using a propane torch, caramelize the sugar until melted and a rich caramel color. Do short bursts of flame and if one area is getting too dark or starting to burn, lift the torch away for a few seconds and then return. Continue until the top is evenly caramelized.
SERVE immediately.