In cooking, frenching is the process of cutting things into long, thin strips, like frenched and fried potatoes. It also means cutting meat back from a bone, cutting meat into strips -- basically to cook something in the manner of French cookery (especially making something ordinary look fancy).

French toast is a bit of a different story because in different countries stale bread dipped in egg and fried has different names, including American and German toast, so the French only get credit for French toast in America -- and one of the earliest known recipes for French toast was called Roman toast -- as in the Roman empire, not the city. You can find a lot of things like this that are attributed to different nationalities in different nations. STDs are often called the (insert enemy country here) disease, or how people sometimes say excuse my French in America when they are cursing. In other countries they have similar sayings when cursing that reference other languages. So basically French toast is saying either, "toast the way those crazy foreigners eat it" or it may trace back to the Norman invasions and be saying "toast the way those rich bastards eat it." This is also probably where French kissing comes from, "kissing in the style of crazy, lascivious, foreigners who can't kiss like normal people."

French fries have an unclear origin. We know that Thomas Jefferson ate potatoes "served in the French manner" in 1806, but we don't know if they were fried. An 1856 specifies the recipe for a dish similar to modern fries and calls them "French Fried potatoes."

Belgian journalist Jo Gerard claims that a 1781 manuscript proves that fries were invented in the Spanish Netherlands (present-day Belgium) in 1680. But this manuscript has not been authenticated and is unlikely to be accurate. The potato did not arrive in that region until the 1730s.

They may have been invented sometime in the 18th century in Flanders and then when transmitted abroad English-speakers misunderstood their country of origin, since Flanders was a part of the French Empire in 1806.