Aussie yum cha is when you take the random shit out of the freezer and chuck enough of it in the oven to make a meal. Can include: pies, sausage rolls, nuggs, spring rolls, dim sims, hot chips. Whatever is laying around in the freezer, and can go in the oven.
Yumcha (means drink tea) is a practice of brunch with tea and dim sum. It's also where people will possibly yell at another friend if they see a friend at another table.