Bring about 1 inch of water to a boil in a wide saucepan with a tight-fitting lid. Add a sprinkling of salt; arrange a collapsible steamer in the pan.
Scatter the beans in the steamer basket in an even layer—stacking the beans on top of each other in a dense layer results in uneven cooking. Cover the pan tightly and steam (Steaming Basics) over vigorously boiling water just until the beans are crisp-tender but still bright green, usually about 7 minutes—go by feel, not strictly by time. Slender beans will steam in as little as 4 minutes.