One method not mentioned is the usage of bio-processing to produce proteins identical to those coming from animal products using only genetically modified microbes.

The advantage here is that you're getting as close to the real thing as you can.. Actually there's no difference from the real thing at the protein level- though fats and things need to be added back from imitation sources to re-assemble to thing you're imitating.

This probably isn't overall cheaper today (vs soy, wheat, etc), but the processes is very inefficient and has a TON of room to be improved upon. At a large scale your inputs are glucose and some microbes. Fermentation does the rest.

It just so happens that's what we're working on at at Culture Biosciences. Shoot me an email if this kind of stuff fascinates you. We're hiring software and hardware engineers. satshabad@culturebiosciences.com