“When it comes to…” is a C1 level phrase that is used to introduce a new idea. It can be used with a noun or gerund.
For example: “When it comes to food…” or “When it comes to eating…”
“When is comes to recycling, I think it is very important that people take responsibility to recycle as much as possible…”
When is comes (3)…….. working on a Sunday, I think that people should be paid extra.