1 tablespoon extra virgin olive oil
1 medium onion, chopped
1 russet potato, peeled and grated
¾ pound cabbage (about 1/2 medium head), cored and shredded
Salt to taste
5 cups water, chicken stock or vegetable stock
1 Parmesan rind
Freshly ground pepper to taste
2 cups low-fat milk
1 cup grated Gruyère cheese
FOR GARNISH:
6 1/2-inch thick slices of French or country bread, toasted and cut into small squares
Minced fresh chives
Heat the oil over medium heat in a large, heavy soup pot. Add the onion and cook, stirring, until tender, about 5 minutes.
Add the grated potato, the shredded cabbage and 1/2 teaspoon salt. Stir together for a minute, taking care that the potatoes don’t stick to the pot, and add the water or stock, the Parmesan rind and salt and pepper to taste.
Bring to a simmer, cover and simmer over low heat for 30 minutes, until the vegetables are tender.
Add the milk to the soup. Stir to combine well and heat through without boiling. A handful at a time, stir the Gruyère into the soup and continue to stir until the cheese has melted.
Taste and adjust seasonings. Remove the Parmesan rind. Serve, garnishing each bowl with a handful or toasted croutons.