Rinse potatoes, peel and cut about 2 cm (approximately 3/4 inch) cubes. Peel carrots and cut into slices.
Heat the oil in a large pan over medium heat, add the potatoes and carrots and cook, stirring frequently, for 10 minutes. Pour in a little hot water and cook another 10 minutes.
Peel and chop the garlic. Add to the pan with the ginger and fry briefly. Stir in turmeric and curry powder. Stir the yogurt with the flour until smooth and add to the potatoes with the peas. Cook over low heat for 10 minutes. Season with lemon juice, salt and pepper. Sprinkle with parsley and serve with rice, if desired.