Served this amazing casserole for Christmas Dinner, along with a salad dressed with Ina Garten’s Green Goddess Dressing. It was posted by Bryan0320 on allrecipes, and although in a 1970s throwback with a can of cream of mushroom soup, it deserves every one of the 4.5 stars it got from over 3000 reviews!  I know I’ll make this recipe often.  (Returning after making it a couple of times and simplifying the process a bit.)

Of course I made a few changes as noted below.

Ingredients

6-8 boneless, skinless chicken thighs
1/4 cup butter
1 Tbsp garlic, crushed
1 Tbsp lemon juice
1 can cream of mushroom soup (10.75 oz.)
4 tsp Italian seasoning, or:
1 tsp Basil
1 tsp Marjoram
1 tsp Oregano
1/2 tsp Rosemary
1/2 tsp Thyme
pinch Garlic Powder
1/2 cup half & half
1/2 cup grated parmesan cheese
16 oz. fresh baby spinach
1/3 cup dried shiitake mushrooms, broken into 1/2 inch pieces (Could just use a package of fresh mushrooms chopped, too.)
1/3 cup sherry (optional if you are using fresh mushrooms.)
6 slices of bacon, diced
2-3 cups shredded Mexican cheese blend, or mozzarella

Bake boneless thighs on a baking sheet at 350 for 20-30 minutes. Remove from oven and set aside. Turn oven heat up to 400 degrees.

At the same time, in a little pan bring sherry and 1/2 cup water to the boil. Add the shiitake mushrooms, and turn down to a simmer for 10-15 minutes until the mushrooms are softened.

In a large pot, fry the bacon until nicely browned. Remove all but a Tbsp of the bacon drippings. Add the spinach and saute until completely wilted. It may take several batches to wilt a whole pound, but just keep adding and  cooking. You can add a little water to keep the pan from burning.  Push the spinach to the edges, and add the butter, garlic, lemon juice, cream of mushroom soup, Italian seasoning and mushrooms. Bring to a simmer. Stir spinach from edges into sauce.  Remove from heat and add half & half and Parmesan cheese.

In a 9×12 baking dish, lay half the spinach/cheese mixture in an even layer. Lay the chicken thighs on top. Pour remaining sauce over the top with Mexican Cheese (or Mozzarella) and bake 20-30 minutes until cheese is melted and lightly browned.