There are a lot of different types of vegetarian burgers (or vegeburgers), available in cafes and supermarkets in several countries of the world.
- Many of these are made of something that, even if "natural" in the sense that it's made from natural ingredients by some process, is not easy to make at home from naturally occurring ingredients. For example, Quorn burgers are made of mycoprotein, and Beyond Meat burgers are made of pea protein (presumably also made by some process that's not easy to do for an ordinary person with a bag of peas at home).
- However, I've also seen a "beetroot burger" which, as far as I know, is made from real beetroots in a straightforward way, and I've also made "bean burgers" at home from ordinary beans (don't remember what type of beans now).
Some non-vegetarian friends (from various countries) have tried to make vegetarian burgers at home before inviting me for dinner, but their attempts with ordinary ingredients like legumes or vegetables normally fell flat, or rather fell apart.
What is the easiest way to make vegetarian burgers with natural easy-to-find ingredients? I.e. no fancy stuff like mycoproteins, just ordinary vegetables and things that can be found in ordinary shops in most countries.