One of my favorite foods is oatmeal. It's a complex carb with a high amount of fiber, so you feel full all morning after eating it. It's dirt cheap. It's incredibly easy to make - you stir some boiling water into it. Thus, you can make it even without a full kitchen, like if you're in a hotel. The taste is kind of bland, nothing special, but you get used to it pretty quickly. If you want to spice it up more, any kind of fruit mixes well into it. If you're training, you can stir in flax seed for higher calories and protein, and then it takes on roughly the taste and texture of soft pretzels.
I love the stuff. I eat it whenever I can, which is pretty often. However, there's one downside of oatmeal - it's brutal to clean if you let it dry on a plate.
It's trivially easy to clean if you clean it while it's hot. Run a sponge over it once, or even just rinse a few times with very hot water. But after the stuff dries, it becomes a nightmare to scrape off.
I try to clean up immediately after breakfast, but sometimes I read, or write, or work on spec'ing something out with breakfast, and I might get lost in thought.
The time needed to clean up the oatmeal goes up drastically the longer you let pass. Clean up right after eating? 20 seconds or so. Three hours later? A few minutes. And if you let a whole day pass? You're going to be scrubbing that bowl in the sink for 10+ minutes.
I've been tracking everything I eat lately, and putting some calorie numbers on them.
Indian food: Rice, chicken, curry, vegetables.. Small banana. 900 cal.
Lunch: Big portion rice, curry sauce, chicken. 1000 cal.
Lunch: Two kinds of vegetables (one in very light curry), piece of chicken. 400 cal.
This is kind of crazy. The only difference is, I ordered more vegetables and didn't get any curry on the chicken.