Two slices of Silver Hills Bakery bread topped with margarine and 1/2 tbsp of peanut butter on each slice would get you about twenty grams of protein for 350 calories or so. Most supermarkets today carry a whole-grain bread that, due to its blend of grains and possibly seeds, contains a lot of protein in each slice.
I prefer to cook on the weekends. I just saw this recipe today: iowagirleats.com/2012/02/16/mini-ham-chees
. I would probably eat six for breakfast, giving me 300 calories and 18 grams of protein. You could easily replace the two eggs with 1/2 cup of egg whites to lower the fat further and add more protein. You could also make them in regular muffin cups (I'm estimating that two regular muffins would equal six mini muffins.)