Cut the beef in strips (remember to cut AGAINST the grain!), marinade with the beef marinade ingredients for 20 minutes.
Meanwhile chop all your ingredients.
Mix the sauce ingredients together in a little bowl.
Heat 1 tsp oil in a hot wok. It needs to be hot before you put anything in there!
Put in the beef (single layered) and cook till it's about 80% done. If your wok is hot this should be quite quick.
Rest the beef in a bowl, wipe clean the wok and put a bit of oil to heat up again.
When the wok is hot, put in the garlic and red chilli and fry for about 30 sec. Put in the green pepper, let it blister in the heat for a bit. You want the pepper still crunchy and not be soft!
Once the pepper skin begin to blister, add pineapple and cook for another minute or so.
Add the beef back in the wok, pour in the sauce mixture and mix it all together.
Add the pickled sugar and mix again.
Add a sprinkle of salt if you like, but taste, taste, taste. You can put a bit more salt or sugar at this stage if you like.
Dish up!