First, run your fingers over the interior of the bowl; if there are any rough patches, you might want to smooth them out with some fine steel wool.  Next, decide whether you plan to use the bowl regularly (say, once a week or so) or only occasionally (as when company comes to dinner).  If the answer is the former, use pure, odorless olive oil (i.e., not extra virgin) in the seasoning process that follows; otherwise, use an ingestible mineral oil (sold in supermarkets as a laxative).  Pour a tablespoon of oil into the bowl and a half-teaspoon of coarse salt.  Take a paper towel and gently scour the interior of the bowl with the salt-oil mixture, using a second paper towel to mop up any remaining oil and wipe the surface dry.  Wait an hour or so and then pour in a teaspoon more of the oil and rub it around the interior of the bowl with your (clean) fingers.  When the surface is well oiled, leave it for ten minutes and then wipe it dry once more with a paper towel.  The bowl is now ready for use.