I got this recipe out of the 1989 All American Brand Name Cook Book, my mother in law gave to me as a Christmas gift the year before I married her son. This is an amazing roast. It tastes delicious! I did change the cooking instructions over the years as my way makes for a much more tender roast. This recipe also works nicely with a round roast. I like to serve it with a side of rice and gravy!
In a large skillet, brown roast in oil. Place in 3-quart roasting or baking pan. (I use a baking pan and wrap roast tight in foil) Add flour to drippings; cook and stir until browned. Add buttermilk, water, bouillon, thyme and pepper. Cook and stir until bouillon dissolves and mixture thickens slightly, about 5 minutes.
Place onions around meat; spoon sauce over meat. Cover; bake 2 hours.
Add carrots and continue to bake for 2-3 hours more or until roast is tender. Add remaining vegetables; bake 15-20 minutes longer or until vegetables are tender.