Brown beef in a large skillet and drain the grease. Allow it to cool. Put the browned ground beef in a large resealable freezer bag. Add the salt, pepper, red pepper flakes, and cilantro.
Add the chopped onions, garlic and green peppers. Pour in both cans of tomatoes.
The bag will be quite full at this point. You may want to prop it up either by setting it in a tall juice container and folding the top of the bag over the edge, having someone hold it open, or using a "baggy rack" to hold the bag open for you.
Drain one of the cans of kidney beans and add it to the bag. Add the other can of beans with its juice. Remove the excess air from the bag and seal. Squish to combine. Freeze.
On the day you want to cook the hearty chili, take the bag out of the freezer. Thaw.
Cover with lid and cook on the stovetop over low-medium heat for 2 hours, stirring occasionally.
When you notice that the chili is looking a bit watery, take the lid off. When it starts to look like it needs to be a bit more watery, add the lid. Repeat this process for the duration of the cooking time.
Don't forget to stir it from time to time. Chili stuck to the bottom of the pot is no fun to clean off!