What should I eat to gain weight?

I’m 16 Years old I am quite skinny I eat chicken etc but am not able to gain weight what to do

I was the same way when I was young. My grandmother used to use “half n half” in place of milk for my cereal/oatmeal every morning. And at night she would feed me ice cream with again “h and h” poured over it or fruit with it as well. I did get used to the richer taste and I put on 5 pounds in no time. Probably not the most nutritious, but it worked for a few lbs.