Crock Pot French Dip Sandwiches. 2-3lb beef roast;4 cups beef broth;2 pkgs Lipton Onion Soup Mix;Italian sub rolls; Provolone cheese slices Put beef roast in crock pot. Add broth & soup mix. Cook low 7-8 hours. Shred, return shredded beef to crock pot for a few more minutes. Slice open bread, place a good amount of beef on one side,top beef with cheese. Broil open sandwich in oven until the cheese gets melted and bubbly. Remove from oven, serve with a ladle of au-jus left in crock pot.