How could I cook industry like foie gras?
Foie Gras is fatty goose or duck liver. There is no machine or process to make it. It is harvested from the animals themselves. Restaurants have providers for their product. You will have to find one for yourself.

I know of no legitimate substitute for Foie Gras that anyone would not care about. People pay a lot of money for Foie Gras and would be quite displeased if they found they were being fed a cheap alternative.

If you are refering to paté made from Foie Gras then you could stretch the final product with the use of chicken livers. I'm uncertain how much cheaper this is though and once again be careful you aren't deceiving anyone.