I also don't tolerate beef too well, and base my protein intake almost exclusively on mackerel (one entire can, bones and all, per day) and wild salmon, and sometimes oysters and tuna, etc. I use grass-fed beef fat to make my cooking oil (is it tallow?), and cut it in half with coconut oil. But a big steak by itself never has done me well. Not sure what it is. Maybe the oily meat just balances things out digestively somehow?
I've actually been thinking lately of experimenting with using spinach mash that's been dried and ground as my source for the sodium nitrate for a batch of bacon. I really wonder how that would work out.