Vegetable samosas

Name: Vegetable samosas
Ingredients: 1 potato, about 150g; 3 tbsp vegetable oil, plus extra for brushing; 1 tsp mustard seeds; ¼ tsp fenugreek seeds; ½ tsp cumin seeds; 1 onion, finely sliced; ½ tsp ground turmeric; ½ tsp ground cinnamon; about 120g white cabbage, finely sliced; 1 large carrot, about 120g, peeled and grated; 100g mixed red and green peppers, cored, de-seeded and finely chopped; 50g frozen peas; ½ tsp granulated sugar; 12 spring roll pastry wrappers, 25 x 25cm; 1 egg, lightly beaten; salt