Season the minced meat with salt and pepper and roll into small balls.
Heat the oil in a stock pot and sauté the onion until translucent. Add the cauliflower, leek, carrot and celery with cayenne pepper and sauté for about 3 minutes while stirring.
Add the thyme, tomatoes and meat stock and simmer over low heat for about 20 minutes. Add the minced balls and let stand for about 10 minutes.