Well, a serving a day of oatmeal should be sufficient to boost your supply. I have recently read somewhere (I forget where right this minute) that oatmeal in any form will boost breastmilk supplies. It does not have to be a bowl of oatmeal for breakfast.
You could make oatmeal cookies (I have a great recipe from the "Feeding the Whole Family" cookbook for a relatively healthy cookie) (or the recipe on the Quaker Oats box is pretty yummy). If you eat meat, you could mix oats into a meatloaf. You could try steel cut, or Irish oats which are a lot chewier and less like mush! You could buy or make granola bars which have tons of oats.
You could also try other whole grains, like quinoa or amaranth I guess and have similar effects.
