Saute mushrooms, butter, onions, celery and garlic, until onions are opaque.
Transfer veggies to large bowl.
Add a bit of broth to pan and scrape up residue from the vegetables, and add to bowl.
Add remaining broth into bowl and add bread, artichoke hearts, parmesan cheese, poultry seasoning and rosemary. Mix well.
Add salt and pepper to taste (I added about ½ tsp of each)
Beat egg in a small bowl and add to stuffing. Mix in. (The original recipe suggests creating a well in the stuffing, breaking the egg into it, and then beating it there, and mixing it into the stuffing. I think my way is easier).
Put stuffing into a lightly greased 9 x 13 casserole dish and place in a 350 degree oven. For moist stuffing, cover with foil, for crustier stuffing, leave uncovered
Bake until lightly browned or heated through–about 45 minutes to an hour.
Notes
You can put in the casserole dish the day or morning before and refrigerate it, cooking for an hour or so when ready to serve. You could switch chicken broth for veggie broth, if you wanted a vegetarian option, and skip the egg if you wanted a vegan option, I guess… Yields 10 cups to serve 12. This works out to 8/10 of a cup per serving. It's easier to just divide your baking pan into 12 equal servings (3 down, 4 across).
Recipe by The Taste Place at https://www.thetasteplace.com/sourdough-parmesan-artichoke-stuffing/