Deep frying the cauliflower in this iconic dish gives it a nuttier flavor and and a firmer texture.
, I find I can happily eat aloo gobi no matter how it's prepared, so long as it's salty enough.
However, when making aloo gobi myself, I have a few preferences. Growing up in New Delhi, my family ate a fair amount of aloo gobi at home, but I invariably preferred the aloo gobi I could get elsewhere, particularly the drier kinds in which the the cauliflower was deep fried instead of stewed, which makes the cauliflower taste nuttier and gives it a firmer texture.
From there, all you have to do is make a quick masala with some whole cumin seed , minced onions, ginger, garlic, green chile, dried fenugreek leaves, ground turmeric, diced plum tomatoes, and water. You'll want to take your time with the onions; you want them brown, which should happen fairly quickly given the relatively small amount of onions and the relatively large amount of oil used to brown them.
During testing, I made the same recipe but without the frying step, just to see whether I thought the deep frying was definitely worth doing, and I can report that it works quite well, but it isn't as good, as the cauliflower is a little less dry and makes the final dish a little watery.