Don't roast cashews on your own if you have never worked with fire outdoors!
To roast the cashews you need to do that outside in a garden area. Keep some sand on the floor and spread it and place the wooden log on top of it and put fire . Please be careful when you do this. Keep a fire extinguisher around just in case for the worst situation!
The log should just catch a bit fire so that it turns into embers without a flame. Spread the embers a bit on the sand area and place the dried raw nuts in-between. For the first time just throw a few into the embers so that you get a feel for it because the nuts can completely burn from inside very quickly.
Keep on mixing the nuts with the surrounding embers and sand. Smoke will appear which is normal and keep on mixing. The nuts are ready when you can hear them sizzle. All that will take about a minute so as I mentioned above be careful because they can really burn fast!
Once you think they are ready, take them out to cool. Then open them, discard the shell and store the seeds in a airtight container.
You can add salt or spices to them for flavor and enjoy them as snack or use them in baked good or curries.