How to Make It
Make the buttermilk ice cream. In a medium heavy-bottomed saucepan over medium-high heat, bring the cream just to a simmer. Remove from the heat.
Meanwhile, prepare an ice bath.
In a large bowl, thoroughly beat together the egg yolks and sugar. While whisking the egg mixture, add ½ cup of the hot cream to the bowl to gently temper the eggs. Whisking constantly, add in another ½ cup of the hot cream. (Continuous whisking prevents the eggs from scrambling.)
Now begin whisking the cream in the saucepan and slowly pour in the tempered egg mixture. Place the saucepan over medium heat and stir constantly with a wooden spoon or heat-proof spatula. Continue stirring until the mixture has reached a temperature of 180 degrees F and is thick enough to coat the back of a spoon.
Strain the custard through a fine mesh strainer into a metal bowl or container. Stir in the buttermilk, vanilla, and salt. Immediately place the metal bowl into the ice bath. Stir occasionally until the custard cools to room temperature. Place the custard in the refrigerator to chill completely, at least 4 hours and preferably overnight.
Process the custard in an ice cream maker according to manufacturer’s instructions. Transfer the ice cream to a lidded container and freeze for at least 8 hours before serving.
To make the strawberry sorbet, make a simple syrup by combining 1 cup of the sugar and the water in a small saucepan over high heat. Bring to a boil, then turn off the heat and let the syrup cool completely.
In a large saucepan over medium-high heat, place the strawberries and remaining ¼ cup sugar. Bring the strawberries just to a simmer and cook, stirring frequently, for about 10 minutes. Remove the pan from the heat and let the strawberries cool to room temperature.
Blend the strawberries in a blender or food processor and strain through a fine mesh sieve to remove the seeds.
Combine the strawberries with ¾ cup of the simple syrup in an airtight container. To make sure that there is the right amount of sugar in the mixture for freezing, complete my “egg test.” Once the flavored liquid and the simple syrup have combined, gently place an uncooked egg (washed and in its shell) into the mixture. If the egg floats, you don't need to add any more simple syrup. If the egg doesn't float, remove it and add a little more simple syrup to the mixture, and place the egg back into the mixture. Repeat until the egg floats. When it passes the test, place the mixture in the refrigerator and chill for at least 1 hour.
Process the mixture in an ice cream maker according to manufacturer’s instructions. Transfer the sorbet to a lidded container and freeze for at least 8 hours before serving.
Make the berry compote. In a small saucepan over medium-high heat, combine the berries and sugar. Once the juices start to simmer, turn the heat down and cook until thickened, 25 to 30 minutes. Stir in the lemon juice. Transfer to an airtight container and allow to cool to room temperature for 30 minutes, then chill the compote in the refrigerator until ready to use.
Make the berry float. Place a spoonful of the berry compote in the bottom of a tumbler glass. Put one scoop each of buttermilk ice cream and strawberry sorbet on top of the compote. Place the fresh berries on top of and around the ice cream and sorbet. Top with the sparkling wine, filling the glass to ¼ inch from the top. Serve immediately.