Place turkey breast in pot, add next six ingredients (broth and spices). Place cover on Instant Pot and place valve in sealed. position.
Set on manual, (high), for 45 minutes. Allow for natural released. Remove lid and shred with two forks. Stir in mushroom soup and add additional broth if needed.
Spread butter evenly over split buns then place on baking sheet under oven broiler for 2-3 minutes until lightly toasted. Use slotted spoon to place meat on buns and crown with a slice of Provolone cheese. Cap hot turkey sandwich with top of bun and serve immediately.
For the Slow Cooker Version
Set slow cooker on medium setting. Add turkey breast, broth and spices and cover and cook for 6-8 hours. Remove lid and shred with two forks. Stir in mushroom soup and add additional broth if needed.
Spread butter evenly over split buns then place on baking sheet under oven broiler for 2-3 minutes until lightly toasted. Use slotted spoon to place meat on buns and crown with a slice of Provolone cheese. Cap hot turkey sandwich with top of bun and serve immediately.
Notes
If meat seems dry at end of cooking, add a bit more (warm) broth. On the other hand, if you have more juice than you want, continue to stir the meet after shredding and a lot of the juice will be reabsorbed by the meat. Finally, if it is still too juicy, sprinkle in a teaspoon of flour or so, stir until desired consistency is reached.