From turtle soup to bog butter, and wee-soaked eggs to toxic mercury, our ancestors had some surprising ideas about what constituted tasty food and drink. Here are some of the more unusual culinary options from days gone by.

Fesikh (or feseekh) is thousands of years old. It’s believed that in Pharaonic times, rather than waste mullet that was washed up on shore after the Nile river receded in spring, the fish was dried in the sun then salted. The result? Fermented fish with a putrid pong.

Washed-up stinky fish may not be to everyone’s tastes but it’s still eaten in Egypt to mark Sham El Nessim, a national holiday celebrating the beginning of spring. It must be prepared by a reputable ‘fasakhani’, as the dish can cause food poisoning and even death if not prepared properly.

The gross-sounding bog butter was actually an ingenious method of preserving food during the Iron Age. The butter was either made with dairy or it was meat-based like tallow. It was stored in wooden containers then buried in a peat bog to prevent it from spoiling.

Because peat bogs are largely acidic, cold and oxygen-poor, they’re remarkably good at preserving. So much so, that centuries-old bog butter is still being dug up (like the one pictured). In 2016, a 2,000-year-old chunk was dug up from Emlagh bog in County Meath, Ireland while other discoveries date back as far as 5,000 years. Much of what is found is still edible.

The Romans had many interesting (some would say alarming) dishes in their culinary lexicon. Giraffe meat and flamingo tongues featured, though these delicacies were only afforded by the rich. Cute dormice were also eaten.

The adorable rodents were so popular that they were kept in a specific jar called a glirarium where they were fattened up before being killed, stuffed with pork and pine nuts, smothered in honey and roasted.

In Roman times, garum was a nutritious condiment made from the fermented fish guts of anchovies, sardines and sprats. Garum was kept in large urns like the one pictured. It was also prescribed as a medicine for certain conditions such as chronic diarrhoea.

Garum’s potent umami tang made it natural flavour enhancer; as a result, the fish sauce was added to many dishes. It could also be drunk.

While some scholars argue that the extent of cannibalism practised by pre-Colombian Mesoamericans has been exaggerated to justify the Conquest, there’s documentation that the eating of human flesh did happen. It's unclear whether the meat was consumed for ritualistic purposes or as a regular food source.

Skeletons have been found with nicks and marks consistent with meat being cleaved off bones and there’s evidence of human barbecues. Boiled and grilled bones from studied remains have also been found from earlier Mesoamerican civilisations.

Virgin boy eggs – eggs boiled in their shells in the urine of young boys under the age of 10 – are a traditional food from the city of Dongyang, China, which dates back centuries. The curing process is similar to the one used to make pidan (century eggs).

The day-long process came about because urine (and especially virgin boys’ urine) was purported to have numerous health benefits. This theory is still believed by some, though the product is now regarded as niche.

Tudor feasts weren’t just about the food – they were displays of great wealth. One culinary fashion was fantastic beasts, which is how the cockentrice came about. The striking dish consisted of half a suckling pig sewn onto half a turkey or capon (castrated cockerel).

There were variations of the cockentrice: sometimes it was a pig’s head and a bird's lower body and legs; other times it was a bird’s head and pig’s bottom half. There are also recipes for a cooked cockerel riding upon a suckling pig ‘steed’. Nope, not weird at all.

Medieval feasts also included tableside theatre and one dish full of drama was live birds in a pie. A large hollow pie was baked then songbirds were put in the cooked pie via a trapdoor at the bottom. When the pie was cut, the birds would fly out into the room, enthralling guests.

Some interpretions of the nursery rhyme 'Sing a Song of Sixpence' suggest the rhyme refers to live bird pie in the line “Four and twenty blackbirds baked in a pie”. Although, the birds weren’t actually cooked alive or eaten but were there to create a spectacle.

The substance ambergris is a waxy mixture of bile and fat excreted or regurgitated by whales. In the late 1600s, it was highly regarded as a food flavouring – it's claimed King Charles II had it with eggs. Ambergris was also added to hot chocolate, jam, lemon sherbet and smothered on roasted game.

As well as being used as a tonic to treat headaches and epilepsy, ambergris was prized for its aphrodisiac qualities. Due to its strong musky scent, it was also used in perfume. Today, many countries have banned it but it’s still sold for obscene amounts of money. In 2013, a 6lb (2.7kg) lump found by a man walking his dog on a British beach was thought to be worth up to £100,000 (around $135,000).

Until some species became endangered, turtles were eaten by wealthy Georgians and Victorians who regarded the reptiles as an exotic delicacy. Turtle soup would often be served in the shells at banquets.

As demand grew, the soup was increasingly made with tinned or dried turtle, or substituted with mock turtle (boiled calves’ heads and brains). Lewis Carroll later immortalised the mock turtle as a fantastical hybrid creature in Alice's Adventures in Wonderland.

Mercury is a chemical element that was imbibed by syphilitic Georgians to cure venereal disease. Throughout history it was also consumed as an aphrodisiac and contraceptive.

What wasn’t known until the early 19th century is that mercury is highly toxic and often did more harm than good. Today, mercury levels in certain fish such as mackerel, swordfish and some tuna are considered high enough to be harmful to our health in large amounts.

Cheesy ice cream may not sound appetising but the Georgians liked their ices in lots of different flavours, including rye bread, burnt sugar and parmesan.

Savoury ice creams and sorbets have made a comeback in recent years and it’s not unusual to find the likes of goat’s cheese or brown bread ice cream on fancy restaurant menus.

Necessity is the mother of invention and when apples or citrus fruit where in short supply, acidic vinegar was used instead to mimic the real thing in 1840s America.

Vinegar pies were commonly made by American Pioneers and during the Great Depression, when they were called ‘desperation’ pies. The end result looks and tastes a bit like a lemon tart.

Before the advent of energy bars there was pemmican, a Cree Indian concoction made from ground dried meat and fat. Fruit or berries were also sometimes added. It was commonly made to preserve food and provide sustenance.

Pemmican could be eaten raw or cooked and because it was highly nutritious, Europeans – especially fur traders and Arctic and Antarctic explorers – ate it for its highly calorific, energy-giving properties.

Indigenous Australians have been eating protein-rich witchetty grubs and other similar grubs for millennia. Witchetty grubs are large, white moth larvae that can be eaten raw (they taste like almonds) or cooked (the skin is similar to roast chicken).

Witchetty grubs may seem revolting to Western palates but indigenous Australians eat them regularly for their nutritionally dense, protein-rich meat. And given the world’s growing population, grubs could become a food of the future.

Sandwiches are an intrinsic part of British food culture but there can be none so mundane as the toast sandwich, which consisted of a slice of buttered toast between two fresh slices of bread.

There's a recipe for toast sandwiches in the Victorian culinary bible, Mrs Beeton’s Book of Household Management. It was served with salt and pepper and deemed a light meal “tempting to the appetite of an invalid”.

During the Second World War, when food was highly rationed, people in Britain had to get inventive with the ingredients available to them. One thrifty culinary trick was using liquid paraffin in cakes, in place of butter and lard.

Liquid paraffin is used primarily in cosmetics, in medicine to treat constipation and to treat colicky horses. In small amounts, liquid paraffin is probably harmless – unlike paraffin (also called kerosene), a fuel that’s toxic when consumed.