Total dork here. I bring breakfast and lunch every day, whether riding or not. When riding, the food goes in one pannier and my purse in the other. If you browse the Container Store, Target or any Ace Hardware you'll find a plethora of food container shapes and sizes. Snapware rules because it prevents spillage. As mentioned on a Simple Living thread, this Salad Shaker changed my life. It's also a great conversation-starter! For breakfast, I have a small stainless-steel container that holds oatmeal, nuts and fruit. Also a big fan of the nut butter/jam sandwich as it can be breakfast, lunch or snack.

Most important is to do as much prep the night before as possible. This includes making the salad and even cutting up the fruit for the oatmeal. Grab-and-go is the only way that works for me.