Couscous "faux caviar"
A very affordable alternative to caviar, original and tasty, often to be seen on finger food menus. It is known as 'faux caviar'. It is obtained by preparing couscous in a way that it still has plenty of bite to it, before being flavoured with a generous amount of butter and, as a second step, with sepia ink. If sufficient care is taken when adding the latter ingredient and mixing with a fork, the result looks like shiny black pearls (they can be made to look even shinier with the addition of some olive oil before serving).
Soy pearls
So-called "soy pearls" are based on the same principle. These are tiny select soy spheres which are boiled and generally sold in jars preserved in oil, or aromatised with spices, yuzu or wasabi. Of course their flavour is a far cry from that of authentic caviar and rather tasteless besides, but the "pearls" lend themselves perfectly to being used as edible garnishes. Another caviar substitute that some refer to as soy pearls as well is made from a thin shell of algae which encloses soy sauce. These beads detonate flavour when you bite into them.
Snail caviar
This is in fact one of the most bizarre examples of 'alternative caviar'. Completely different from sturgeon, its flavour is earthy and reminiscent of mushrooms; it is obtained by allowing snails to mate in highly controlled environments and the resulting eggs are subjected to a meticulous selection. So much so that, at the end of the day, their cost is practically on a par with that of traditional caviar: here we are talking roughly about 1800 Euros per kilo. However, there are some varieties that are sold in little 50 gram jars (about a couple of spoonfuls) at 100-120 Euros (2000-2400 Euros per kilo). Besides, snail caviar targets a very up-market niche of enthusiasts who have appreciated this product ever since it was first launched in the early '80's.