This article is from the Food Preserving FAQ, by Eric Decker firstname.lastname@example.org with numerous contributions by others.
Freezing cooked meat, except in combination dishes where a solid pack
can be prepared for freezing, is not recommended. Work carried on in the
foods research laboratory of the University of Illinois as well as in
other foods laboratories indicates that higher quality is obtained if
uncooked rather than cooked poultry and meat are frozen. Carefully
controlled experiments have shown that this is true for deep fat and
oven fried chicken, braised beef round steaks, ham patties and loaves,
and rib and loin pork roasts. In general, poultry and meat roasted or
fried have a more attractive appearance and better flavor than that
cooked before freezing.
Precooked frozen vegetables have been rated as being inferior to freshly
cooked and to blanched frozen vegetables. The few exceptions are products
that can be solidly packed such as vegetable purees and mashed potatoes.
In the latter case freezing is not recommended because it takes almost as
long to thaw and reheat mashed potatoes for serving as it would to prepare