Yes, you can use pre-fried onions in Hyderabadi Biryani. Using pre-fried onions will slightly reduce the 'dum' cooking time as they are already cooked and only need to meld their flavor into the biryani.
The 'dum' cooking process in Hyderabadi Biryani is crucial for infusing the flavors and aromas throughout the rice and meat. The fried onions, also known as birista, contribute significantly to the overall taste. When using freshly fried onions, their moisture and flavor are released during the dum, enriching the biryani.
If you opt for pre-fried onions, they are already cooked and have less moisture. Therefore, the dum time can be slightly reduced. Typically, a Hyderabadi Biryani might require a dum of 45-60 minutes. With pre-fried onions, you can reduce it to 30-45 minutes. The exact time will depend on the quantity of biryani and the heat level. Keep a close watch to prevent the bottom from burning. The key is to ensure the rice is fully cooked and the flavors are well integrated.
When using pre-fried onions, sprinkle a little milk or saffron-infused water over them before layering them into the biryani. This helps to rehydrate them slightly and release their aroma more effectively during the dum process, mimicking the effect of freshly fried onions.