Place the uncooked rice in a medium-sized resealable bag and seal.
Chop the onion and green pepper.
Add the browned ground beef that you cooked the night before, tomatoes, onion, green pepper, and seasonings to a large resealable bag. Squish everything in that bag together.
Remove the excess air from the bag and seal.
Staple the medium bag of uncooked rice to the large bag above the seal.
On the day of cooking, take the meal out of the freezer and thaw it.
Carefully take out the staples and add the contents of both bags to the slow cooker. Add 1 cup of water and stir.
Cook on low for 4-5 hours or on high for 2-3 hours.