Young person seeking extra work for one month (beginner in English, but speaks French and Italian)

I'm hosting a 17y old French student (male) who's in London for the Summer. He's lovely, speaks French and Italian but his English is really poor and he's here to learn for his exams next year. He's working in a Central London kitchen, however they're not busy and only giving him half of the work they promised before he came to London. As a result he's struggling financially and considering going back to France. He'd only need a few extra hours of work a week to make it through the Summer, can anyone advise or help?