Thinly slice the leek.
Heat the oil in a large saucepan and gently sauté the leek for 5 minutes.
Meanwhile, chop the carrot and shred the cabbage.
Add the carrot pieces to the leek, then cook for another 3-5 minutes (under cover).
Pour in the stock, bring to the boil, then simmer over low heat for 5 minutes.
Add the frozen vegetables, bring to the boil again, then add the shredded cabbage and fresh green beans (if fresh version is used). Cook for 3-5 minutes, then turn off the heat.
Add the minced garlic and chopped parsley, stir well.
Serve the soup with a dash of apple cider vinegar or lemon juice.