Preheat oven to 400
Place the chicken, sage, salt and pepper in a pan and cover it with the broth. You need to make sure the chicken is covered with the broth. If not add more chicken broth or what I did in this case was add water.
Bring the chicken to a simmer, cover and cook 30-45 mins or until done.
Take chicken out and shred once it is cooled. (I use 2 forks. Makes it much easier and you can even do it when it is hot.)
Mix the cream of chicken, hashbrowns, cheese, 1/2 cup of the french onions, frozen veggies, melted butter, and sour cream together in a large bowl until mixed. At this point too, if it seems to dry for you simple adds some of the cooking liquid which is what I did in this case.
Pour into a greased 9x13 baking dish and top with remaining french onions.
Cover and bake 30-45 or until potatoes are done.
Remove foil and bake for an additional 5 minutes.
Remove from oven, let cool and enjoy!