Heat 1 cup of the milk, salt, and the sugar in a small saucepan to steaming, stirring to dissolve the sugar. In a mixing bowl, whisk together the egg yolks. Pour ¼ of the milk mixture into the egg yolks, whisking constantly until smooth. Pour the tempered egg yolk into the saucepan and stir constantly over medium/high heat until the mixture comes to a boil and thickens. Remove from heat and pour into a bowl. Whisk in the remaining ½ cup milk, heavy cream, grape juice, lemon juice, and lavender oil. Refrigerate until fully chilled.
When the base is chilled, freeze in an ice cream maker according to manufacturer instructions. Scoop the ice cream into a freezer safe container and freeze for at least 6 hours or overnight.
Let sit on the counter for 10 minutes before scooping.
Recipe by The Kitchen McCabe at https://www.thekitchenmccabe.com/2015/05/25/lavender-lemon-ice-cream/