One of my favorite quick fixes is guacamole and tortilla chips. I use a modified version of Alton Brown's recipe. Since guacamole doesn't keep (it turns brown and disgusting-looking within 24 hours, usually), I just cut and mash one avacado and eat the whole thing. I reduce the spices from his recipe by 1/3 to make it work. (Actually, I usually just sprinkle in what looks good without measuring, but the first time I made it, I reduced the spices by 1/3.) I also don't let it sit for an hour and I only use dried ingredients and skip the tomato altogether. It's absolutely amazing if you take the time to follow the recipe exactly, but it's still pretty tasty, and a lot quicker, this way.
If you can't eat tortilla chips because of a corn allergy, you could substitute pita chips, bagel chips, or bean chips, I think. Let me know how that is if you try it. Also, it's more filling if you add some leftover taco meat, too.