This is a unique way to make a wood bowl. All you need is a grinder (sanding disc), an impact drill, a screw, a vise, and a piece of wood. Jigs are not necessary!! Very easy to make the bowl even for beginners because of using the grinder that doesn't require any skills compared to bits.
It might be better to start with a small piece of wood to learn the skill.
If you try this way, please do it at your own risk.
I also make a handmade hairbrush and a wood plate by using this method.