Because the overall cooking time of this stew is anywhere from 1 hour and 30 minutes to two hours (depending on how long you let the meat simmer and how tender you like your vegetables) the meat sometimes does not get as tender as I would like; thus the choice of sirloin roast pieces. Feel free to use your favourite stewing beef.
If you like onions in your stew and would like to eat them, before returning all the beef to the pot and adding water sauté chopped onions until translucent and then proceed.
Taste as you go! If you think there is a need for another bouillon cube or more Kitchen Bouquet, go for it! I know, that sometimes the meat is so flavourful that the bouillon cubes and/or the Kitchen Bouquet are not required.