Step 1

Preheat oven to 400 degrees F. Coat a 9-by-13-inch (or similar 3-quart) baking dish with cooking spray.

Step 2

Heat 2 teaspoons oil in a large nonstick skillet over medium heat. Sprinkle chicken with 1/2 teaspoon salt. Add half the chicken to the pan and cook until browned on both sides and just cooked through, 8 to 10 minutes total. Transfer to the prepared baking dish. Repeat with the remaining chicken.

Step 3

Add the remaining 1 teaspoon oil and onion to the pan. Cook, stirring often, until softened and light brown, 4 to 5 minutes. Add curry powder, ginger, pepper and the remaining 1/4 teaspoon salt; cook for 1 minute. Sprinkle with flour and stir to coat. Add broth and milk. Bring to a simmer, stirring constantly, until thickened, about 2 minutes. Remove from the heat and stir in peas, mayonnaise and lemon juice (or vinegar). Pour the sauce over the chicken.

Step 4

Wash and dry the pan. Melt butter in the pan over medium heat. Remove from the heat and stir in bread cubes. Toss to coat. Arrange the bread on top of the casserole.

Step 5

Bake the casserole until it is bubbling and the croutons are golden brown, 35 to 40 minutes. Let stand for 10 minutes before serving.