My son wanted patty melts for his birthday last night. I had some frozen brisket trimmings on hand, but was feeling lazy so I used the food processor to grind it up and just eyeballed it. I wanted a fine grind since I was cooking them on a hot griddle and they got a great crust. Topped on rye with a mess of grilled onions, homemade american cheese, and then griddled the sandwiches till nice and brown. Was gonna take pics but got too hungry.
I think if you're not grinding too much you can do a very good job with the food processor.