Bob's your uncle (sometimes elaborately Robert's your mother's brother) is an expression commonly used mainly in Britain and Commonwealth nations.
Typically, someone says it to conclude a set of simple instructions to mean, "And there you have it", or "You're all set". For example, "To make a ham sandwich, just put a piece of ham between two slices of buttered bread, and Bob's your uncle". (Cf. voilà and presto.)
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