To remove one part from another as the yolk from the white of an egg?

To remove, for example, the yolk from the white of an egg is to separate the egg.

This is achieved by using an egg separator, which catches the yolk in a bowl-like section while allowing the white to run through into a container below; you can use a cup to catch the white. This is the neatest and quickest method.

Or you can carefully crack the egg in half and, holding over a cup or bowl, tilt the shell halves as you tip the yolk back and forth from one to the other until the white has all run off and just the yolk is left in one half of the shell.

Some cooks like to crack the egg into their hand and pass it back and forth between hands, allowing the white to run off between the fingers until just the yolk is left in the palm of the hand. You need a reasonably large bowl to take the egg white if you separate the egg this way, a cup won't do, and it's messy, but some people like the feel of raw egg. Wash your hands thoroughly in cold water if you use this method.

All utensils used with raw egg should be initially cleaned well with cold - never hot - water. You can wash them later in hot water when you do the final cleanup of the kitchen.