Season the chicken on both sides with salt and pepper. Coat in breadcrumbs well, pressing firmly to pack the breadcrumbs on.
Heat oil in a nonstick pan over medium heat. Cook the chicken golden brown on both sides to an internal temperature of 160 degrees using a thermometer. Remove and set aside.
Add shallots, mushrooms, and garlic to pan (add a little more oil if needed). Sauté until mushrooms are soft and beginning to brown. Add the broth, scallions, and butter to the pan. Bring to a high simmer to build flavor and thicken the liquid to a creamier consistency. Season with salt to taste.(Dissolve a small amount of flour or cornstarch in an equal amount of cold water and mix it into the sauce a little at a time to thicken if needed).
Cut the chicken into strips and spoon the sauce over top. Serve with bread.