1747—a small outlay or risk ventured in the hope or expectation of a significant return—a metaphor from fishing, in which sprats are used as bait to catch larger fish—in early use with the words ‘salmon’ and ‘herring’ instead of ‘mackerel’
UK, 1983—‘Ruby Murray’, the name of a Northern-Irish singer (1935-1996), is rhyming slang for the noun ‘curry’, denoting a dish of meat, vegetables, etc., cooked in an Indian-style sauce of hot-tasting spices and typically served with rice.
Northern England—a filled or open sandwich—originally (1827): a slice of bread spread with butter—composed of ‘butt-’, from the noun ‘butter’, and the suffix ‘-y’, forming diminutive nouns
Lancashire, England, 1833—a faggot, a meatball, “a compound of onions, flour, and small pieces of pork” (The Liverpool Echo, 20 August 1880)—probably one of the common dishes humorously named after daintier items of food
Liverpool, England, 1939—scouse without meat—“from the general early sense of ‘blind’ meaning ‘deficient’” (Liverpool English Dictionary)—‘scouse’, shortened form of ‘lobscouse’: “a dish of hashed meat stewed with potatoes and onions; an Irish stew” (English Dialect Dictionary)
‘knuckle-sandwich’ USA, 1940—‘knuckle-butty’ UK, 1972—a punch to the mouth (or to the stomach)—the image is of a sandwich of knuckles being forced into the mouth (or into the stomach) of the person who is punched
UK, 1870—a very hard ship’s biscuit—refers to the fact that these sea-biscuits were particularly carried by Liverpool merchant ships; likens the shape and hardness of these sea-biscuits to those of pantiles, i.e. roofing tiles curved to an ogee shape