The verb hash, which dates back to the mid-17^th century, is from French hacher, meaning to chop, to mince, itself from the feminine noun hache, meaning an axe. (English hatchet is from the diminutive of hache, hachette.)

The literal sense of the noun hash is a dish consisting of meat which has been previously cooked, cut into small pieces, and warmed up with gravy and sauce or other flavouring. It is first recorded in the diary of the English naval administrator Samuel Pepys (1633-1703), on 13^th January 1663:

I had for them [= my guests], after oysters, at first course, a hash of rabbits, a lamb, and a rare chine of beef. Next a great dish of roasted fowl, cost me about 30s., and a tart, and then fruit and cheese. My dinner was noble and enough.

The sense of the noun hash was extended to a mixture of jumbled incongruous things and to a mess, often in the phrase to make a hash of, meaning to make a mess of, to bungle. (This sense development is similar to that of mess.)

But, curiously, the theologian and cardinal John Henry Newman (1801-90) used the phrase (which was new to him) in what he believed was a positive sense in a letter that he wrote from the University of Oxford on 2^nd October 1833:

We are getting on famously with our Society, and are so prudent and temperate that Froude writes up to me we have made a hash of it, which I account to be praise.

The phrase to settle someone’s hash means to deal with someone in a forceful and decisive manner. Here, the person dealt with is compared to a dish of food that has to be attended to, and the verb settle means to reduce to order. In A Complete Collection of Genteel and Ingenious Conversation, According to the Most Polite Mode and Method Now Used at Court, and in the Best Companies of England (London, 1738), the Irish satirist, poet and Anglican cleric Jonathan Swift (1667-1745) played on two different meanings of settle:

Lady Smart: Then, why don’t you marry, and settle?
Colonel Atwit: Egad, Madam, there’s nothing will settle me but a Bullet.

The phrase itself is first recorded in the caption to Olympic games or John Bull Introducing his new Ambassador to the Grand Consul (London, 16^th June 1803), a British political cartoon by the Scottish painter and caricaturist Isaac Cruikshank (1756-1811). It shows Napoléon Bonaparte giving an ambassador a blow in the face with his clenched fist, saying:

There Sir take that, and tel [sic] your Master, I’ll thras [sic] every one who dares to speak to me I’ll thrash all the World D— me I’ll, I’ll I’ll be King of the Universe.

The astonished ambassador exclaims:

Why this is club Law; this is the Argument of force indeed the little Gentleman is Dêrangé [sic].

John Bull, however, is introducing a prize-fighter as his representative, telling the little Corsican:

There my Boy is an Ambassador who will treat with you in your own way – but I say be as gentle with him as you can.

The pugilist looks on his adversary with contempt:

What! is it that little whipper snapper I am to set too [= to] with. Why I think the first round will settle his hash.

Meanwhile, the Austrian ambassador says:

The Monarch I represent, will return this insult with becoming Dignity.