Both of these soups are made using a chicken stock base.
I like to buy a whole chicken at the beginning of the week, carve up the pieces I want to grill for main dishes (drumsticks, etc.), then throw the rest into a pot of water. Bring it to a boil, then simmer it for a few hours. The chicken will fall off the bone for the most part... you can scrape any stubborn bits, and then throw the carcass away.
Of course, if you want to cheat you can buy low-carb chicken stock that's ready-to-go. (But I think the soups are far better with actual chicken chunks in them)
So, once you've got your batch of broth, you can make tons of different soups from it. Here are my two favorites. (Note that amounts are estimations, as I never really measure anything. Everything is flexible-- do what tastes good to you!)
HOT and SOUR SOUP
Heat up your chicken broth. Add veggies if you want (suggestions: bean sprouts, fennel or cabbage, a bit of onion.)... though it works just as well without.
Add...
One large clove of minced garlic per serve.
One tablespoon of minced fresh ginger per serve.
A few slices of fresh green chili per serve (careful! these can be very hot!)
Salt and Pepper to taste.
When you serve, add...
Plenty of freshly chopped cilantro and mint leaves.
Juice from half of a lemon (= 1 carb)
STRACCITELLA
This is a classic Italian soup... that just so happens to be super low carb!
Again, heat up your chicken broth.
Add...
One clove of minced garlic per serve (more or less to taste)
A handful of fresh spinach per serve.
Salt and Pepper.
Simmer the soup until the spinach is cooked.
Then, bring it up to a boil again.
Once it's boiling, crack one egg (per serve) into the soup, and stir it around. The egg will cook into solid little strings (hence the name "straccitella"), and become almost like tiny noodles.
Serve your soup, and while it's still piping hot, add plenty of freshly grated parmesan. (make sure it's a medium grate, not the grainy, powdery kind. This way it melts better.)
This one tastes good with a tiny squeeze of lemon just before eating.
Enjoy!