Place roast in the slow cooker, in a large bowl whisk together the broth, the seasoning and gravy mix. Pour over the roast.

Set slow cooker to low and allow to cook for 10 to 12 hours or on high for about 4 1/2 hours.

When done cooking remove the roast from the slow cooker. Mix cornstarch into about a half cup of water, once completely combined pour into the gravy and stir until it thickens to your desired consistency. Shred the beef and add it back into the gravy.

Split french bread in half, place meat on bottom half of the bread. On the other half spread mayo top with lettuce, tomato and pickles. Close and eat and enjoy!