I usually get a yoghurt parfait and a coffee from McDonald's. That's under 300 calories of protein though.
You can make a breakfast sandwich in about two minutes at home. Get a smallish microwavable bowl, preferably something with a flat bottom like this that will cook the egg into a handy circle. Toss bread in toaster, crack and scramble a raw egg in bowl. Microwave egg for ~30 seconds (you'll have to find the best time for your oven). You may want to give the bowl a quick hit of cooking spray before putting the egg in so it slides out easier. When toast pops up, put a slice of ham and cheese on one piece and microwave for 15 seconds to warm meat and melt cheese. Drop egg on top, add other slice of bread and done. Longest part is waiting on your toaster.
I see you wanted portable so you could either eat it on the go or make it at work (assuming you have a microwave & toaster) in about as much time as it takes to heat up a frozen breakfast sandwich.
Edited, Oct 10th 2012 10:35am by Jophiel