You can do them either way - all ingredients except rice frozen uncooked (raw) or frozen with all ingredients half-way cooked. You can even freeze them in baking dishes with the tomato sauce and all ready to pop into the oven.

My personal preference is cooked rice, lightly browned beef and onions (not fully cooked), stuff the blanched and cooled peppers, pour on the tomato sauce and freeze it all.

But I would blanch the peppers if planing to freeze. Destroys the enzymes that can cause early spoilage.

Dave

Thanks Dave - I've frozen cooked rice with raw meat and seasonings when I've had extra (I don't brown the meat when I'm cooking stuffed peppers or cabbage), but I've never frozen stuffed peppers before, and though I froze leftover stuffed cabbage after it was cooked, the reheated version was soggy and I didn't want that to happen to these peppers. I think I'll skip the tomato sauce (add when defrosted) for the same reason.