Heat the oil or ghee in a large casserole. Add the onion, salt, spices and sugar and cook over low heat for 5-7 minutes or until the onion has softened. If the pan is getting too dry, you can add a little chicken broth.
2 tbsp vegetable oil, 1 large yellow onion, 1 tsp salt, ½ tsp brown sugar, ½ tbsp garam masala, 1 tsp ground cumin, ¼ tsp ground turmeric
Stir in the tomato paste, minced garlic and ginger and stir well.