1 (22 ounce) jar Alfredo sauce (2 1/2 cups)
3 cups less-sodium chicken broth
1/2 cup sour cream
12 ounces (about 6 cups) uncooked medium egg noodles
1 cup frozen diced onion, thawed
1 1/2 - 2 cups chopped cooked turkey (or chicken)
8 ounces sliced fresh mushrooms
2 teaspoons minced garlic
1 cup (4 ounces) grated Swiss or Gruyere cheese (or more, as desired)
Chopped fresh parsley