Place the beef stew meat with onion, peppercorns, salt and water in the pressure cooker. Place the cover on the pressure cooker, and pressure cook on high for 30 minutes, until the meat is absolutely tender and falling off the bones. If meat is frozen cook for 70-80 minutes.

Prepare and cut your vegetables

Depressurize the pressure cooker. If necessary, skim any foam from the broth. If you wish, cook the broth in advance and refrigerate. Any solidified fat will be easier to skim.

Add the vegetables and cook on the simmer function until the potatoes are fork tender. Season to taste with fish sauce or salt. Serve hot over rice.