Instant Pot Instructions:

1. Turn Instant Pot to sauté setting. When display says HOT add in the beef and break it up. Add in the onion. Brown for about 5 minutes.
2. Stir in the water and scrape bottom of pot so that nothing is sticking. Turn off Instant Pot. Dump in the beef base, salt, pepper, garlic powder, Worcestershire, ketchup and green pepper. 
3. Cover Instant Pot and secure the lid. Make sure valve is set to sealing. Set the manual/pressure cook button to 2 minute. When time is up move valve to venting. Remove the lid. 
4. In a small bowl stir together the cornstarch and water until smooth. Turn Instant Pot to saute and stir in the slurry. It will thicken quickly. Stir in the cheese. 
5. Scoop onto toasted buns and serve. 

Slow Cooker Instructions: 

1. Add beef, onions, water, beef base, salt, pepper, garlic powder, Worcestershire, ketchup and green pepper into slow cooker. Use a spoon to break up the meat. Stir. 
2. Cover and cook on high for 3-4 hours. Break up the meat with a spoon. 
3. In a small bowl stir together the cornstarch and water until smooth. Turn slow cooker to high and stir in the slurry. Cook without the lid until thickened. Stir in the cheese until melted. 
4. Scoop onto toasted buns and serve.