I have never browned meat for slow cooker ( to me its pain in butt and dirty another pan lol)
I have known others to use frozen meat.

I have no made a rissotto in mine so not sure.

I do sausage casserole, beef stroganoff, chicken curry, lamb shanks are all favs here in slow cooker.

Not made soup as I do that on stove as make so much!!

Enjoy it makes life so easy when at 1700 you think hmm only need to cook rice or pasta to go with dinner!