If it's maple, it's safe to just leave it without a finish, although it may wear out faster.
I would not use a vegetable oil; it will go rancid over time.
Behlen's food safe finish is fine, as is salad bowl finish, but I don't know how well they stand up to heat. Mineral oil will work too. At the least, you could use one of those and just give it another application of oil a couple times a year.