Heat oven to 200 degrees F. Have a large deep roasting pan ready.
Season the beef on both sides with a mixture of the dill seed, salt, and pepper. Place in roasting pan.
Pour the water and vinegar around the roast. Cover pan tightly with foil and roast for 5 hours.
Remove roast to a cutting board to rest while you prepare the gravy. Sprinkle the drippings in the pan with the 3 Tablespoons flour and blend well. Stir in the sour cream. (If it needs to be thicker, place some of the sauce in a measuring cup or small and whisk in more flour then stir into the pan). Stir in the chopped fresh dill.
Slice roast and serve with the sour cream sauce. I served it with buttered wide noodles and sprinkled with poppy seeds alongside roasted carrots. We loved it!
Recipe by The Culinary Cellar at https://theculinarycellar.com/double-dill-pot-roast/