Per Bonita's request
I make soup every Sunday while cooking dinner and divide it into portions for the week. I find it fills me up nicely at lunchtime and is (generally) low calorie!
Here's one of my favourites:
Roasted vegetable soup.
Roast a red pepper, a yellow pepper, a red onion and a punnet of cherry tomatoes.
While they are roasting, boil a diced potato and a chopped carrot in some lowsalt vegetable stock. Once the vegetables are starting to brown at the edges, add them to the pot, simmer for a few minutes and blend! If I am not dieting, I add some chopped chorizo and frozen peas at this stage and simmer again.