Creamy Chicken, Mushroom and Wild Rice Casserole
- 4 tablespoon(s) olive oil, plus more for the dish
- 1 1/2 cup(s) wild rice blend, such as Lundberg
- 1 large onion, chopped
- 1 pound(s) white or cremini mushrooms, sliced
- 2 large cloves garlic, finely chopped
- 2 tablespoon(s) fresh thyme
- 1 package(s) (9- to 10-oz) spinach, thick stems discarded
- 1/2 cup(s) fresh flat-leaf parsley, chopped
- 3 tablespoon(s) all-purpose flour
- 3 cup(s) (2%) milk
- 8 ounce(s) (2 cups) Gruyère, grated
- 1/4 teaspoon(s) cayenne pepper
- Kosher salt
- 1 (3- to 3 1/2-lb) rotisserie chicken
- Toasted sliced almonds, for serving
Heat oven to 375°F. Oil a 3-qt or 9 x 13-in. casserole dish. Cook the rice according to package directions.
Meanwhile, heat 2 Tbsp oil in a large skillet over medium heat. Add the onion and cook, covered, stirring occasionally, until tender, 6 to 8 minutes. Add the mushrooms and cook, tossing occasionally, until tender, 5 to 6 minutes. Stir in the garlic and thyme and cook for 1 minute. Transfer to a large bowl and toss with the spinach and parsley.
Wipe out the skillet and heat the remaining 2 Tbsp oil over medium heat. Sprinkle the flour over the top and cook, stirring, for 1 minute. Gradually whisk in the milk. Simmer, whisking often, until thickened, 4 to 5 minutes. Remove from the heat and add the cheese, cayenne, 3/4 tsp salt and 1/4 tsp pepper; stir until the cheese melts and the sauce is just smooth.
Shred the chicken, discarding the skin and bones. Add the chicken and rice to the cheese mixture and toss to coat. Fold in the spinach mixture. Transfer to the prepared casserole dish. Cover with foil and bake until bubbling around the edges, 45 to 50 minutes. Let stand for 5 minutes. Sprinkle with the almonds before serving, if desired.