Broccoli Wild Rice Casserole

INGREDIENTS

• 2 cups Uncooked Wild Rice
• 8 cups Low-sodium Chicken Broth, More If Needed For Thinning
• 3 heads Broccoli, Cut Into Small Florets
• 1 pound White Button Or Crimini Mushrooms, Finely Chopped
• 1/2 cup (1 Stick) Butter
• 1 whole Medium Onion, Finely Diced
• 2 whole Carrots, Peeled And Finely Diced
• 2 stalks Celery, Finely Diced
• 4 Tablespoons All-purpose Flour
• 1/2 cup Heavy Cream
• 1 teaspoon Salt, More To Taste
• 1 teaspoon Black Pepper
• 1 cup Panko Breadcrumbs