Place a heavy-bottomed pan over low heat and add the butter. Let it melt gently without browning.
Once melted, drop in the green cardamom pods and sauté them for about 1 minute to release their aroma.
Stir in the suji and cook, stirring frequently, for 8 to 10 minutes until it turns golden and begins to release a nutty fragrance.
Add the raisins and continue cooking for another 2 to 3 minutes until they plump up slightly.
Sprinkle in the sugar and stir well. Let it cook for 3 to 4 minutes so the sugar begins to melt and blend into the mixture.
Slowly pour in the milk while stirring continuously to avoid lumps. Keep the heat on medium-low.
Let the mixture simmer for 15 to 20 minutes, stirring occasionally, until it thickens and the butter starts to separate from the halwa.
Once the mixture reaches a thick consistency and the butter visibly separates, turn off the heat and let it rest for a few minutes before serving.
