Turn your pressure cooker on saute/brown mode.
Season the boneless ribs with your favorite BBQ seasoning.
When the pot is hot, add some oil to the bottom. Brown the meat on each side in batches. When browned, removed from the pot onto a plate. Continue until all the meat is browned and removed to a plate.
Turn the pot off. Add the beef broth, apple juice and liquid smoke. Scrape the bottom of the pot to remove all the brown bits (deglaze). Be sure to get all you can off so the pot will come to pressure.
When you've deglazed add the ribs back to the pot.
Pressure on HIGH for 30 minutes. Let the pressure come down naturally for 10 minutes. Release the remaining pressure.
Remove the ribs to a plate.
Mix together the corn start and water to form a slurry. Turn on the saute feature. Add the slurry to the liquid in the pot. Stir until you reach the desired consistency. Add the ribs back to the pot.
Serve with rice, potatoes, polenta, whatever!