Clean the Brussels sprouts, split large heads. Also clean the carrots and cut into thin slices. Peel the potatoes and cut into bite-sized cubes. Peel the onion and cut into narrow wedges. Wash the parsley, shake dry and chop.
Heat the oil in a saucepan and steam the onion vigorously with a little nutmeg. Stir in the tomato paste and pour in the vegetable stock. Add the prepared vegetables, bring the liquid to the boil and cook the vegetables over medium heat for about 20 minutes. Season the stew with salt and pepper and sprinkle with the parsley.