Start with established steam
Bring a shallow layer of water to a steady simmer beneath a steamer basket. Add eggs in one layer and cover. Timing from the moment the lid goes on is more repeatable than allowing eggs and water to heat together.
Match time to the centre
For large chilled hen eggs, about 6–7 minutes is a useful starting point for a soft centre and roughly 11–13 minutes for firm. Basket material, egg size, altitude and how tightly the lid fits all affect the result.
Cool promptly
Move finished eggs to cold water to slow carry-over cooking. For peeling, crack the shell all over and begin at the broad end. Steam can help separation, but very fresh eggs may still cling to the membrane.