Preheat oven to 350 degrees Fahreneheit (180 degrees Celsius). In a large skillet, toast bread crumbs in oil until light brown and crisp. Add in French-fried onions and dry mustard. Stir to combine and then set aside.

Place remaining ingredients in a 9×13-inch (23×33-cm) oven-to-table casserole dish or baking pan and stir until well combined. Cover tightly and bake for 50 minutes, or until vegetables are tender, yet still a little crisp.

Uncover and mix gently until pan juices are evenly distributed; sprinkle crumbs over vegetables. Return to oven an additional 10 minutes, uncovered. Remove from heat and serve.