Slow Cooker Mushroom Stuffing

I rarely stuff my birds as I've only made two turkeys in my entire life. I cook the stuffing in a crockpot and let it cook for several hours while I do everything else.

Ingredients:
1 cup butter
2 cups finely diced yellow onion
2 cups finely diced celery
1/4 cup fresh parsley, chopped
12 ounces baby portabello mushrooms, diced
12 cups dried bread crumbs
1 teaspoon poultry seasoning
1 1/2 teaspoons dried sage
1 teaspoon dried thyme
1/2 teaspoon dried marjoram
1 1/2 teaspoon salt
1/2 teaspoon ground black pepper
4 1/2+ cups chicken stock
2 eggs, beaten

Melt butter in a saucepan and sautee onion, celery and mushrooms until tender. Mix all ingredients in a medium sized crock pot and cover. Cook on high for 45 minutes, then reduce heat to low and continue cooking for 4 to 8 hours. If the stuffing gets too dry, add more stock a little at a time.