Heat the oil (if using) in a large soup pot, then add the onion and cook for about 5 minutes until soft but not browned.Note: If using a non-stick pot omit the oil and add a splash of water if the onions start to stick.
Add the potatoes and cook for a further 2 minutes, stirring often.
Stir in the paprika and cook for 1 more minute, then add the stock, water and tomatoes. Bring to the boil, then reduce the heat and simmer for 10 minutes.
Add the chopped cabbage and pepper and simmer for a further 5 minutes. Taste and season further if desired.
Divide into bowls and serve. Will keep in the fridge for up to 5 days.
Notes
To make this recipe completely oil free, use a non-stick soup pan to saute the onion and potatoes.
Stir in the cabbage last and let it wilt naturally with the heat of the broth. This will help keep the cabbage from having a mushy texture.
If you are omitting the potatoes from the recipe for a low carb version, be sure to use less water as potatoes help thicken the soup naturally.
Variations
Spice your diet cabbage soup up by adding a pinch of cayenne pepper or a diced jalapeno to the mix. A big pinch of dried chili flakes works too.
Add some fresh herbs like rosemary, thyme or basil.
Use a mix of napa cabbage and white cabbage for a slightly different flavor and texture.
Add more non-starchy vegetables such as broccoli, asparagus, mushrooms and bell peppers.
Give it a light curry flavor by adding 1 tablespoon of your favorite dry curry seasoning powder.
Give this cabbage soup a Middle Eastern flavor with a teaspoon of Baharat spice blend.
Increase the protein content by adding some canned chickpeas, shredded chicken or cubes of extra firm tofu (toss them in a little cornstarch first, spray a frying pan with low-calorie oil and pan fry until slightly crispy).