1 can (10 3/4 ounce) cream of chicken soup (see Substitute below)
1 1/2 teaspoons curry powder, or more, depending on the strength of your curry powder
1/2 cup mayonnaise
2 tablespoons dry sherry or white wine (or more to taste)
Kosher salt, to taste
Fresh ground pepper, to taste
1 cup grated sharp Cheddar cheese
Preheat oven to 375 degrees. Grease a 2 quart baking dish (I like to use an 8 by 8-inch or 7 by 11-inch dish).
Spread spinach on the bottom of the prepared dish.
Cut chicken into bite-size pieces and distribute evenly over spinach.
In a small mixing bowl, whisk together the soup, curry powder, mayonnaise and sherry. Season to taste with salt and pepper. Spread evenly over top of chicken and bake for 20 minutes.
Sprinkle Cheddar cheese over the top and continue baking for an additional 20 to 25 minutes, or until chicken is done, casserole is
Make ahead: Casserole can be prepared up 24 hours ahead covered and refrigerated. Bring to room temperature before baking.
Substitute for cream of chicken soup: 3 tablespoons butter 3 tablespoons flour 1/8 tsp garlic powder 1/8 tsp onion powder 1/3 cup whole or 2% milk
In a small saucepan, make a white sauce: melt butter over low heat. Whisk in flour, garlic powder and onion powder and cook for 3 minutes over low heat, whisking constantly. Whisk in milk and cook over medium heat, stirring, until it begins to thicken. Whisk in curry powder, mayonnaise and sherry. Season to taste with salt and pepper. Spread evenly over top of chicken and bake per instructions above.