Soy Beans

I recently read in a cookbook that soybeans make a good meat extender
by mixing it in with ground meat in your recipies. The idea is to make
what meat you purchase be able to me used in more meals or feed more
people with out much cost increase or losing the protien nutrient.
This seems logical and economical.

Has anyone ever tried this? If you have how was it? Any suggestions
for preparation or seasoning?

Thanks,
Jenny