First, rub the chicken with a little olive oil (1 teaspoon should do the trick for a pound or so), salt and pepper. Heat another teaspoon of olive oil in a medium skillet over medium heat, place chicken breasts in and cook until edges are opaque, about 10 minutes. Flip to the other side, then cover the pan, lower the heat and cook for another 10 minutes. Finally (and this is important) let the chicken rest for at least 5 minutes before you cut it or all the juice you made the effort to keep in will come running right out.