As with most phrases from olden days there is a flip side of the coin or in this case 'gravy boat'.
This 'slang saying' fits my 'Aladdin' style gravy boat...'profit or money easily obtained or received unexpectedly.'
First...it is a collectible made by J.A. Bauer Pottery founded in Paducah, Kentucky in 1895. Bauer Pottery moved to Los Angeles, California in 1909. My gravy boat's incised Los Angeles stamp confirms it was made after 1909.
It's value ranges from $12.00 to $49.00 depending on which online vintage dish monger you search. So back to the slang saying about 'money easily obtained or received unexpectedly'...the 'gravy' in this boat led to an unexpected priceless Bauer Mixing Bowl.
It was likely made in the 1930's which fits the time period in which my husbands grandmother would have mixed and let rise many loaves of bread. Now you know why it is priceless!
Life may be 'meat and potatoes', but thank goodness for the gravy and it's unexpected blessings!