As you say Ummm as long as you are cooking it to a high enough temeprature inside to kill of any bacteria that may be frozen inside, it is perfectly fine.
You can't really do it with whole poultry or large joints is that you would struggle to get the inside of the meat cooked properly before the outside was burned or dried out, but not impossible.
Cubed meat should be fine - remember, you can buy frozen pies and they are perfectly safe to eat and need to be cooked from frozen.