Finely chop the onion and garlic.
Dice the carrot and celery.
Peel and dice the sweet potatoes.
In a large, heavy-based pot, heat the oil, then gently sauté the onion, celery and carrot for 5 minutes until soft, then add the garlic, sweet potatoes and herbs of your choice.
Stir for a minute, then add the passata and the vegetable stock.
Bring to a boil, then add the pasta.
Simmer, uncovered, for 10 minutes.
Meanwhile, shred the cabbage.
Add the cabbage and lentils and cook for another 3-5 minutes.
Taste the soup and season to your liking.
Serve warm.