When to start mixing foods?

I feed one kind at a time, for 3 Consecutive days to make sure my son isn’t allergic to it. Eg: carrot for 3 days. Once he is ok with it, i will mix with potatoes for 3 days to make sure he’s ok with potatoes.

When introducing new foods, do it one a time. But once baby’s okay with these foods, feel free to mix:)