Step 1

Preheat oven to 350 degrees F. Coat a 9- x 13-inch baking dish with cooking spray.

Step 2

In a large skillet over medium-high heat, heat oil; saute mushrooms and ham 5 to 7 minutes, or until they begin to brown.

Step 3

Sprinkle chicken on both sides with garlic powder and pepper; place in baking dish. Spoon mushroom mixture evenly over chicken.

Step 4

In a medium bowl, whisk soup, milk, thyme, and onion powder. Spoon over mushroom layer. Sprinkle with cheese.

Step 5

Bake 25 to 30 minutes, or until chicken is no longer pink in center.