I do Beef Stroganoff in slow cooker.
Beef
onion
Carrots
Packet sachet
garlic
chilli crushed
red wine
crushed tomatoes
tomatoe paste
wostershire sauce
what other vegies you want I tend to add peas and corn and mushroom about 40 mins before end.

Stir thru some sour cream and done.

Have frozen it before and it was ok.

Sausage casseroles I do as well but never frozen them as well as lamb shanks and chicken curry.