Chicken Asparagus Gratin Recipe

Ingredients

• 2 boneless, skinless chicken breast halves, cut into bite-size pieces
• 1 lb. asparagus, trimmed and cut into 1? pieces
• 8 button mushrooms, quartered
• 1 tablespoon olive oil
• 3/4 teaspoon salt, divided
• 1/2 teaspoon ground black pepper, divided
• 3 scallions, chopped
• 4 tablespoons butter
• 6 tablespoons all-purpose flour
• 2 cups 2% milk, divided
• 1 cup half-and-half or 2% milk
• 2 tablespoons chopped fresh thyme or 1 1/2 teaspoons dried
• 3 tablespoons grated Parmesan cheese
• 2 tablespoons seasoned dried bread crumbs