Mushrooms Should Be 1 4 Oz Can Of Mushroom Pieces Drained And Chopped. Lightly Salt And Pepper Flank Steak. Spread One Side With Mustard. To Prepare Stuffing, Heat Vegetable Oil In A Frypan, Add Onion And Cook For 3 Minutes, Until Lightly Browned. Add Mushroom Pieces; Cook For 5 Minutes. Stir In Parsley, Chives, Tomato Paste, And Bread Crumbs. Season With Salt And Pepper And Paprika. Spread Stuffing On Mustard Side Of The Flank Steak, Roll Up Jelly-Roll Fashion And Tie With Thread Or String. To Prepare Gravy, Cook Bacon In A Dutch Oven Until Partially Done. Add The Meat Roll And Brown On All Sides, Approximately 10 Minutes. Ad Onions And Saute For 5 Minutes. Pour In The Beef Broth, Cover Dutch Oven, And Simmer For 1 Hour. Remove Meat To A Preheated Platter. Season Pan Juiceswith Mustard. Salt And Pepper To Taste; Stir In Catsup. Serve The Gravy Separately.