Thaw frozen strawberries in a bowl. Once thawed, mash with a fork or in a food processor or blender. If using fresh strawberries, remove stems, and puree in the food processor or blender. 

Add pureed strawberries to empty Ninja Creami pint container. Add sugar and heavy cream. Stir with a fork until completely combined. Make sure that the contents does not exceed the max fill line. Place pint lid on top.

Place into the freezer, ensuring that the pint is resting flat. Allow to freeze for at least 24 hours.

Once completely frozen, remove the lid from the container and place into the Ninja Creami outer bowl. Secure the black lid with blades (you should hear a click).

Plug in machine. Place bowl onto the Ninja Creami machine and make sure it is secure (again, you should hear a click). 

Press the sorbet button and allow the go through the whole cycle, it will take just a few minutes. 

Remove lid, if the mixture looks crumbly, place lid back on and click the respin button.

Once finished, serve immediately.