Melt half of the butter in a skillet over medium heat.
Add onions and celery and cook, over medium low heat, partially covered, until tender and lightly colored, about 25 minutes.
Transfer to a large mixing bowl.
Melt remaining butter in the same skillet. Add the apple chunks and cook over high heat until lightly colored but not mushy.
Transfer apples and butter to mixing bowl with the onions and celery.
Crumble the sausage into the skillet and cook over medium heat, stirring until browned.
With a slotted spoon, transfer to the same mixing bowl with the onions and apples. Add the remaining ingredients to the mixing bowl and gently combine.
Spoon into a casserole dish.
Bake for 35 minutes at 350.
Serve immediately.