All of our cashew trees were here when we moved in. Now, let me tell you about growing cashews. Yes, you can grow them from the seed (the nut). Often if I haven't picked them up, they begin sprouting and I get small cashew plants scattered over the lawn. These get pulled out.
Now for the rest of the story! If you are in a country that doesn't have cashew trees growing you may be thinking that you can plant a nut and it will grow. It won't, they have been heat treated. Even bags of nuts claiming to be raw cashews won't. From my research there are only a handful of people who can extract the nut without heat treating in some way, either boiling or roasting it. The acid that surrounds the nut inside the shell is dangerous.
If you go to a health food shop and a bag says 'raw cashews' buy it and plant one. If it sprouts, I will be surprised.