This is another great soup that I make often.
The original recipe can be found here on Epicurious.com, but I tweaked it slightly (of course!) to use a jar of my canned diced tomatoes instead of the chopped fresh tomato and I used my own canned chicken stock. Other than that, though, I followed the original recipe pretty faithfully.
This is another soup that freezes rather well, although the orzo does tend to absorb more of the stock if it is frozen, thawed and re-heated, causing the soup to thicken up a little, but I find that makes it all the more satisfying and rib-sticking on a cold winter's day. I will make a batch of this on the weekend every few weeks or so and portion it out into 2-cup freezer containers ready to grab on my way out the door on weekday mornings. Another great lunchtime standard.