Completely cool the risotto before getting started.
Portion out the risotto into the amounts you will want to use when defrosted.
Scoop each portion into its own freezer bag or freezer safe container
Zip the bag shut once you have pressed any air out of it. If using a container, press the lid on top of it.
Grab a marker and write the date on the bag or container.
Stick your package into the freezer.
Notes
Cool it off: ensure that it it thoroughly cooled off before starting to package it up. Otherwise you will get condensation in the package and it can create freezer burn.Portion it out: determine the portion size you will need and package in those portions. This way you only defrost what you need.Keep air out: ensure you have removed any air from the bag before zipping it shut to minimize exposure to air. If using a container try to make sure the container is sized so there is only a few inches between the risotto and the lid.