First let me say that leaving something on the counter to thaw is about the worst possible approach. (no offense to your mom) It is also potentially dangerous, as it lingers in dangerous temperature ranges for a long period of time, and can leave you with unevenly thawed items.
There are two safe ways to thaw frozen meat and fish.
- Simply moving it to the fridge and allowing to come up to fridge temperature over a more extended period time. This method is best for thinner items of less mass (e.g.- flank steak, fish fillet, chicken cutlet). Larger items can require ridiculously long periods of time, and often will thaw unevenly - For instance, if you were to thaw a whole chicken in this manner, the outside will thaw after 8 hours, while the remainder of chicken can take as long as 32 hours more to thaw- so the surface of your chicken, is thaw for a much longer period of time. In other words - your chicken essentially sits in the fridge for a lot longer than it needs to. While it IS in the fridge, even chicken in the fridge can still get funky.
- Submerging in a vessel, with a trickle of running cold water. This works well and quickly for everything as long as it's in an airtight package (vacuum packed or a zip top bag)**. The trickle of water is essential to keeping the process moving along. What it does is create a convection (movement of energy) in the water bath, ensuring that the water in contact with the item you are thawing is warmer. If that trickle isn't happening, your frozen object just brings down the temperature of the surrounding water, you might even notice that ice form on the surface.
**- the exception to the airtight package is a shrimp, which I thaw out directly in the water. Other proteins will be affected by extended contact with water. For instance, salmon's texture will be come mealy and have trouble browning in a pan.