1. 5 tablespoons butter
2. 1 onion, cut into thin slices
3. 3 carrots, cut into thin slices
4. 3/4 pound mushrooms, cut into thin slices
5. 3/4 teaspoon salt
6. 1/4 teaspoon fresh-ground black pepper
7. 3 1/2 tablespoons flour
8. 1 1/2 cups canned low-sodium chicken broth or homemade stock
9. 1/2 cup half-and-half or light cream
10. 1 tablespoon chopped fresh marjoram
11. 1 1/3 pounds boneless skinless chicken breasts, cut into 1-inch cubes
12. 2 cups fresh bread crumbs
1. Heat the oven to 400 degrees F. In a 10- or 12-inch ovenproof frying pan or large saucepan, melt 3 tablespoons of the butter over moderate heat. Add the onion and carrots and cook, covered, stirring occasionally, until the onion is translucent, about 5 minutes. Add the mushrooms, 1/4 teaspoon of the salt, and the pepper. Cook, covered, stirring occasionally, for 5 minutes longer.
2. Stir the flour into the vegetables. Whisk in the broth, half-and-half, marjoram, and the remaining 1/2 teaspoon salt. Bring to a simmer and continue simmering until the sauce starts to thicken, about 2 minutes. Remove from the heat and add the chicken. If using a saucepan, pour the mixture into an 8-by-12-inch baking dish.
3. In a medium saucepan, melt the remaining 2 tablespoons butter. Remove from the heat and stir in the bread crumbs. Sprinkle the buttered bread crumbs in an even layer over the chicken mixture. Bake in the oven until the crumbs begin to brown, 10 to 12 minutes.