Spread and enjoy!
This is one of a number of things I've discovered that help me survive as a broke, busy, vegetarian grad student. I keep a tupperware of mixed (50/50) pesto and tomato paste in the fridge. It looks awful (nasty brown) but tastes great and I can make a sandwich from it in only a few seconds.
Its better with a baguette if you have it, but more expensive that way, of course.