I use Howard,s Bees wax (Butcher block conditioner) which is a mix of Bees wax adn mineral oil as a base. Thus it is a 2 in one solution. Bees wax forms a tougher protective layer than mineral oil.
Would only use ONly mineral oil if the wood has starved (really dry) for this I prefer to use Boos Mystery oil.. Basically a mix of tung oil and Mineral oil. Tung oil should enhance the beauty of the grain and contrast of the wood. It does change the color of wood slighly. Walnut oil.. the food safe version would not change the color of wood. SO if you are happy with teh color of the wood, contrast adn the grains popping out at you.. just mineral oil is the way to go...
IF you prefer a tougher coating.. John Boos does offer sort of polyurethane coating ( EZ~DO, Non toxic for food contact) which is also classified as food safe. I use it mainly on the sides of my cutting board
Have fun
D