Instant Pot Instructions: 

1. Pour broth into Instant Pot. Add beef into Instant Pot. Salt and pepper the beef to taste.
2. Cover Instant Pot and secure the lid. Make sure valve is set to sealing. Set the manual/pressure cook button to 60 minutes for a chuck roast or 30 minutes for london broil. When time is up let the pot sit for at least 15 minutes then move valve to venting. Remove the lid.
3. Move the meat to a cutting board. 
4. In a small bowl stir together cornstarch with equal parts water until smooth. Turn Instant Pot to saute and add in the cornstarch slurry until gravy has thickened. Salt and pepper the gravy to taste or if needed add in a little better than bouillon beef base. 
5. Toast the bread.
6. Shred the beef. 
7. Scoop some beef on top of a piece of toast, top with another pieces of toast. Cut into triangles and then drizzle the sandwich with gravy. 
8. Eat and enjoy!

Slow Cooker Instructions: 

1. Pour broth into slow cooker. Add beef into slow cooker. Salt and pepper the beef to taste.
2. Cover and cook on low for 8-10 hours for chuck roast or 4-5 hours for london broil.
3. Move the meat to a cutting board. 
4. In a small bowl stir together cornstarch with equal parts water until smooth. Turn slow cooker to high and add in the cornstarch slurry and stir. Let thicken without lid for 10-15 minutes. Salt and pepper the gravy to taste or if needed add in a little better than bouillon beef base. 
5. Toast the bread.
6. Shred the beef. 
7. Scoop some beef on top of a piece of toast, top with another pieces of toast. Cut into triangles and then drizzle the sandwich with gravy. 
8. Eat and enjoy!