Just checking in to make sure we're not completely dead...
So, when cooking stuff like yu choy or gai lan, greens that have a leafy part and a thicker stem, one good tip is to separate the leafy part from the harder part when stir-frying.
Then you cook the stems first for a minute before throwing in the leaves. It helps if you use tongs to manipulate the greens because you have greater control.
Make sure the pan is hot so that you get that extra flavour and make sure your ventilation fan is on high!
Don't forget to salt!