At first I attached a baloon inside the cooking utensil which is made of clay. After wearing latex gloves, I spread glue all over a ball of twine with my fingers and wrapped the twine around the baloon-utensil system. I only left a small area at the bottom of the utensil uncovered in order to make lamp change easier. When the twine was fully dry and stuck on the baloon surface (after some hours), I popped the baloon and took out the utensil any left parts from the baloon. Now there is a curved surface of twine because of the baloon. Finally I passed the wire from a hole at the top of the utensil, connected the lamp and that's it!