Here's a recipe I tried a few years back. You can adjust it to suit your own tastes.
1/3 cup butter
1 cup onion, chopped
1 cup celery, chopped
1/2 teaspoon poultry seasoning
2 tablespoons parsley, freshly chopped
1/2 teaspoon garlic salt
1/2 teaspoon sage
1/4 teaspoon dried thyme
1 (8-ounce) can mushroom stems and pieces, drained
6 1/2 cups bread cubes (sourdough, French or any bread will work)
1 (15-ounce) can cream of mushroom soup (or cream of chicken, onion or celery soup)
1 1/2 to 2 cups chicken or vegetable broth
1 egg, beaten
Sauté onions, celery and mushrooms in butter until tender, about 5 to 6 minutes. Combine remaining ingredients, determining the amount of broth you'll need by the moistness of your bread cubes; add egg last. Pour mixture into crockpot. Cover and cook on HIGH for 45 minutes. Turn heat to LOW and cook for 5 to 8 hours.