A food processor will make chopping the vegetables easier.
1. Prepare the vegetables: thinly slice the onions; finely chop the cabbage; shred the carrots.
2. Heat the oil and butter in a saucepan over medium heat. Add the vegetables, sugar, salt, and pepper. Stir well, then cover and cook 25 min over very low heat.
3. Pour in the broth, bring to a boil, then cover and simmer 15 min. Pour in the milk, then adjust the seasoning.
4. Ladle the soup into bowls and serve.
The soup keeps up to 7 days in the refrigerator or up to 3 months in the freezer. Milk may be added when the soup is reheated.
This soup is delicious and simple to make . . . but . . . I found out that my husband does not like cooked cabbage (only likes raw in salads) . . . you learn something new every day.