Is it possible to cook an egg with the eggshell or a boiled egg?

No. Cooking an egg in the eggshell or cooking a boiled egg can cause steam buildup in the whole eggs and may cause them to explode.

This is Very Dangerous! It can also cause an explosion or shock wave within the oven cavity resulting in the glass tray (turntable) breaking. It can possibly damage the oven or cause injury. Reheating sliced hard-boiled eggs and cooking scrambled eggs is safe.