1. English (or any other language) as a second language
There are millions of people coming to the country who need help leaning English. As a native English speaker you can help, even if you're not a formally trained language teacher.
2. Computer application
There are endless computer applications out there and so many people who need help learning how to use them. Sure, most computer have tutorials, but no small number of people need more hands on help, and might be willing to pay you to provide it.
Yes, there are plenty of cooking shows and a range of cookbooks that could stretch around the world, but none of that squares with the fact that more people are eating more meals in restaurants than ever before!