Combine the Keto Chow, allulose, nut milk, heavy cream, egg white powder, and lemon juice in a pitcher or blender and blend with whisk or blend well until all the dry ingredients are blended and the allulose has all dissolved.
Pour the mixture into a shallow metal dish, a metal loaf pan works perfectly for this. No need to cover the pan.
Place the pan in the freezer and set a timer for 30 minutes.
When the timer goes off, pull the pan out of the freezer and stir the sherbet mix, taking care to scrape the sides of the pan where the sherbet will freeze first. Mix the chilled bits into the center of the sherbet and mix together thoroughly. Stir to break up any ice crystals that have formed.
Return the sherbet to the freezer and continue taking it out and stirring it well, scraping down the sides of the pan, every thirty minutes until the sherbet has a thick, frozen texture that is hard to stir. The sherbet will have visible ice crystals and an almost stretchy-elastic feeling. It will take at least three hours to fully freeze in a standard freezer.