Rub roast with garlic powder, paprika, brown sugar and salt. Place in base of Microwave Pressure Cooker. Add onion slices to Microwave Pressure Cooker. Cover with beef broth and add apple cider vinegar. Seal Microwave Pressure Cooker and microwave on high for 25 minutes. Let pressure release naturally before opening.
Plate and serve
Cut roast into shreds. Serve warm on desired bun topped with cooked onion and white cheddar cheese.