In a large ziploc bag or in a large glass plate, combine ⅔ cup of the V-8 (reserve rest for later use) and the meat marinade. Place meat in the marinade and let sit, turning once, while preparing vegetables.
Peel and cut onions into wedges. Scrub potatoes and carrots. Slice carrots into 1 or 2-inch pieces. Slice celery in pieces the size of the carrots; set all aside.
In a Dutch oven over high heat, heat the tablespoon of oil. Remove roast from marinade, reserving the marinade. Add meat to hot pan and sear on both sides.
Add the marinade and onions to the roast in pan. Reduce heat, cover and simmer gently for 45 minutes. Add potatoes, carrots, and celery. Stir in remaining V-8 in can and the ¼ cup of water. Cover again and simmer gently for 2 hours or until the meat is very tender, stirring occasionally, and adding small amounts of water, if needed. (I didn't need to add any).
Remove pan from burner and transfer roast and vegetables to a serving platter. Cover with foil and keep warm.
For gravy, pour the juices into a 2-cup glass measuring cup. Spoon off any fat, and add water if necessary to make 1-1/2 cups of liquid.
In a small measuring cup, stir together the ½ cup cold water and flour until blended. Return pan to heat, add the 1-1/2 cups of liquid and the flour mixture. Cook and stir until thickened and bubbly, then boil for 1 minute. Pass gravy at the table. Serves 6-8.
Note: I found that no salt or pepper is needed. The V-8 and meat marinade are enough. Also, you could add sprigs of fresh herbs like thyme sprigs and a bay leaf to the pan while simmering.
Recipe by The Culinary Cellar at https://theculinarycellar.com/easy-stovetop-pot-roast/