As for lunch, there is no lunch. It's the simplest choice I have to make all day.
At dinnertime, I can always pull some breakfast options, but it's usually not necessary. Most broth-based soups have fewer than 150 calories per cup. Frozen diet dinners can also offer some good options under 300 calories, if you want to eat pre-made meals.
When I have the time and desire to cook something, a 3oz chicken breast and some steamed veggies do the trick.
So you have to skip lunch one day EVERY week?
I know you're probably still not over the skipping lunch part, so let's talk about it.
Skipping lunch isn't as bad as it sounds. When you plan to eat nothing, then there are no hard decisions to make over whether to go to Chipotle, the falafel cart, the dollar menu, or [insert your favorite lunchtime spot here]. It saves money. It saves time, too. I don't have to interrupt my work to go out and get something to eat.
Since I'm not eating lunch, I usually don't go for the Krispy Kreme donut on a fasting day. I like to eat something that's going to keep me full longer, and that, by default, means I'm eating healthier since loading up on sugar isn't going to provide enough sustainable energy throughout the day.