Wash the bell peppers. Cut away the flesh from the stem and the seeds. Dice, thinly slice, or half the bell peppers, however you prefer them cut for eating later. Pat them dry with a paper towel.
Transfer the peppers to a baking sheet, spreading the pieces apart so they touch as little as possible. Place in the freezer for 1 hour.
Remove the baking sheet from the freezer and transfer the peppers to an airtight bag or container. Squeeze all the air out of the bag and seal. Set back in the freezer until you're ready to use them.
Video
Notes
For best quality, store bell peppers in a zip top plastic bag, reusable silicone Stasher bags, or an airtight container in the freezer, and use frozen bell peppers within 3-4 months.