James, the difference between pan frying and deep frying is simply the amount of oil you use.
To pan fry you don't want the oil to come more than half way up the sides of whatever it is your frying. In other words, simply don't cover it all the way with the oil.
And as far as using the cast-iron inside, and getting it really hot before you put your item in, one word of caution, turn on the vent-a-hood, open windows, and disconnect the smoke detector 'cus brother, you ain't never seen smoke like that will create!! Really, that technique is best done outside, using a gas grill for your heat source if at all possible. You'll notice, especially if you live in an apartment, the vent-a-hoods generally aren't even vented completely to the outside air source, and are therefore essentially useless.
Again, the best way to do a quick defrost on something like fish or chicken fillets, is how I described earlier. Put no more than two to four fillets into a ziplock type bag, and submerge them in a sink full of warm, but not hot water for a short period of time. It usually shouldn't take more than 30 to 40 minutes for a typical serving-size fillet to defrost doing this, you really shouldn't leave it over 40 minutes though.
