An ex had the smaller example of incorrectly asking for "un préservatif" when she meant "un préserve".
One of her friends was half of a multi-nationality couple, I think it was French and Irish, and the punchline was their kid, at a beach, yelling, in a strong Irish accent "Look mummy! Phoques!"
If by "un préserve" they meant a preserve/marmalade then in French that's "une confiture" (or "marmelade" but it's less somewhat rare). I don't think "un préserve" is a word...
Although I may be misremembering the exact word as I have a GCSE grade D from 23 years ago, her French is much better than mine as she lived in Paris for a few years.
One of her friends was half of a multi-nationality couple, I think it was French and Irish, and the punchline was their kid, at a beach, yelling, in a strong Irish accent "Look mummy! Phoques!"