It depends on how broad your definition of "recipe" is.
First, as Cos Callis pointed out, a home cook won't be affected even if a recipe was patented. IP law (=intelectual property) is a matter of civil law, not criminal law. If you hit someone over the head, this is criminal law and the country where this happened will sue you and put you in jail even if the victim says to please not do it because they don't want you to go to jail. You are guilty of a crime the moment you did it.
In civil law, you can do whatever you please. But if somebody comes and says you hurt them (by breaking a contract, infringing on their trade mark, etc.) they sue you for damages. In Europe, you pay for their losses and trial costs. In the USA, they get awarded punitory damages which are usually multiple times their losses. But in either case, no patent holder has a financial interest in sueing a home cook (remember that sueing torrenters is a financial loss for RIAA even when they get 5-digit sums per song). And this being civil law, you are not guilty of anything until they point theif finger at you, even if what you did would be enough for a judge to find you guilty in court.
A restaurant, on the other hand, could have something to fear if recipes were patentable. A patent can be rewarded on either a device or on a technological process. A food item is not a device, so this is not possible. It would be feasible to see a recipe as a technological process, but to get a patent on it, it should be new and have some complexity. This is both not true for the processes used in traditional home and restaurant recipes. Whisking egg whites is as unpatentable as the wheel. Lasagne bolognese as a whole is unpatentable too, as well as newer variations of it. And even if a completely new recipe is invented, it will probably not be complicated enough, or will just consist of unpatentable steps.
The cases where a patent can be granted is in industrial scale food production. The machines which are used there can be certainly patented as devices. But the process itself can also get patented. For example, producing the mix for reconstituted mashed potatoes is covered by patents.
U.S. Patent 1025373, titled "Dehydrate Potatoes and Process of Preparing the Same", and describing a product that was to be reconstituted in hot water, was applied for in 1905 and granted in 1912.
Flake-form instant mashed potatoes date back at least to 1954, when two United States Department of Agriculture researchers were issued a patent for "Drum drying of cooked mashed potatoes" (U.S. Patent 2759832), which describes the end product specifically being "as a thin sheet or flake".
In 1962, Canadian scientist Edward A. Asselbergs was issued U.S. Patent 3260607, entitled "Preparation of dehydrated cooked mashed potato", for a particular industrial method of producing the product.
All of this is independent of trademark law. Trademark law means that you can het sued for selling "Hines catch-up", no matter whether you put ketchup ofr milk in the bottle. But you can sell ketchup made with their recipe with another name, and neither trademark nor patent law makes it illegal.