Wash the ash gourd. De-seed, peel and grate the pulp.
Take a kadai or a deep bottomed pan, add the grated ash gourd and cook on low heat till water evaporates.
Stir occasionally to avoid sticking to the bottom and burning. This process will take around 30 minutes. Remember to monitor continuously.
While the ash gourd is getting cooked, heat a small tadka pan on another stove and add 1 teaspoon ghee to it. Add raisins and remove them after they get puffed. Similarly fry cashewnuts and keep aside.
Check the other kadai where the ash gourd is getting cooked. If the water has evaporated, add sugar and mix well. The sugar will start melting, cook till the mixture is dry.
After the sugar and ash gourd mixture starts drying, add ghee and mix. Keep stirring till the ash gourd halwa leaves sides.