Are they just steaks cut from the ham, or are they salted and cured?
If they are steaks cut form the ham and arfe fresh, not cured here's some answers.
The best methods for a tough piece of meat are either tenderizing and quick or a slow braise.
For quick you need one of those multi-bladed needle type tenderizers. They make about 50 penetrations at once. Then a marinade, this too will helps in tenderizing tough cuts. Then quick on the grill or in the frying pan.
For a braise, dust the meat with seasoned flour. Fry quickly in some oil on both sides to sear the outside. Drain off most of the oil. Saute onions, garlic, celery, carrots, and some peppers. Add 1 cup of white wine and cook for 1 minute. Add 4-6 cups of chicken broth, some fresh thyme and rosemary, then the steaks. Make sure to smother them in the liquid. Place a lid on it and bring up to the boil. Either reduce down to a simmer and cook for 2-3 hours, or place in a 300 degree oven for 2-3 hours. Remove the steaks and thicken the gravy if you like. Serve with smashed potatoes or rice pilaf.
Hope this helps.