eggs in moonshine

Probably from the name of a dish, referred to in 16th- and 17th-century English cookbooks, made of egg yolks lightly poached in sweetened rosewater. See also moonshine, culinary sense (US). https://web.archive.org/web/20160721010231/http://www.foodsofengland.co.uk/eggsinmoonshine.htm

• "You may discourse of Hermes' ascending spirit, of Orpheus' enchanting harp, of Homer's divine fury, of Tyrtaeus' enraging trumpet, of Pericles' bouncing thunderclaps, of Plato's enthusiastical ravishment, and I wot not what marvellous eggs in moonshine: but a fly for all your flying speculations when one good-fellow with his odd jests, or one mad knave with his awk hibber-gibber, is able to put down twenty of your smuggest artificial men, that simper it so nicely and coyly in their curious points."
• "[…] your Majesty knows I think the Horn—and that bit of broken stone over there—and your great King Peter—and your Lion Aslan—are all eggs in moonshine."

• pie in the sky