It's absolutely delicious, and very easy to make, once the initial roasting step is finished. Unfortunately, for most people (including myself), roasting is a huge pain. You have to dry roast it over medium low heat (low heat if you're not lightning quick on your feet) in a wok. It takes quite a while, and you must stir it constantly. As you're standing there and stirring that thing endlessly, there's other steps to preparing to make the uppuma that you're delaying, such as chopping the onions, or getting the rest of your counter space cleaned off, so that when everything is done, you don't end up frantically searching for a space to put the freshly roasted semolina flour, which then burns. Why didn't you think of this before? That would have only made sense, seeing as how you've just spent the better part of a half hour roasting this thing.
And now you're doubly irritated, because that was the last of your semolina, and you do have rice, but that involves even more time (an hour, to be precise, if you're talking brown rice), and you're hungry right now, so you angrily throw the pot, semolina and all, into the sink, scream and cry for a good solid 20 minutes, and then run down to the bodega downstairs, and anger-buy a bag of tortilla chips and a jar of salsa, which you proceed to eat between sobs.
Totally not speaking from experience.
All this can be prevented, if you will use your oven to roast the semolina. I discovered this trick on accident when I was at my brother's house in VA. His wife was making up a batch of uppuma as a lunch thing, and had asked me to roast the semolina for her. I asked her why she didn't just use her oven for it. She mentioned that the oven was being used as storage at that moment, and would I give her a sec to clean it out.
With rare exceptions, Indians who were raised in the South Indian tradition tend not to trust ovens terribly well. When coming to the USA, and making the odd bake sale dish, or birthday thing for the kid's school thing, they'll tend to use the oven to store pots and pans, and promptly ignore its other function: perfect roasting thing.
You see, when you roast anything on the stove, you're dealing with the vagaries of your cooking vessel. For one thing, not all the food is going to be in contact with the heat, which is coming from below, heating your cooking vessel, then heating your food. In an oven, the cooking vessel does get hot and help your food to heat, but the ambient temperature is hot as well, making the food heat evenly. Furthermore, because air is not as good a conductor of heat as water is, you're going to get a more steady and gradual roasting.
There's a reason why you should do your roasting in the oven: the margins aren't quite so razor-sharp as they are on the stove. If you miscalculate by a few mere seconds while roasting on the stove, you risk burning the whole thing, and making a mess. If you misjudge the oven, you still have some wiggle room to fix your mistakes.
Mind you, there are a couple of caveats before we venture into the oven's door:
1) Always double and triple check the temperature of the oven before putting anything in. If your recipe calls for 350°F, and your oven is set at 375°F, you're going to be in a world of pain when the food gets finished so much faster.
2) When roasting something like semolina, which is a flour, don't ever fill your baking sheet completely full. For one thing, the thicker your stack of food, the longer it will take to get everything roasted. For another, you have a much more likely chance of spilling a fair bit onto your floor on your way to and from your oven, and then your sister-in-law grumbles and mutters as she has to clean up yet another mess. Again, totally not speaking from experience.
3) USE. A. TIMER. I cannot stress this enough. With the oven, you don't have those visual cues to keep you going. It's a self-contained environment, where you'll likely miss something if you're not timing yourself. Initially, set the timer for a lower setting, and check frequently. Don't set it for longer until you're confident that it will all work out.
For me, the whole roasting process took a total of 45 minutes. Mind you, this is because I had set the initial times for 7 minutes, and then finally for like 12 minutes. For the first 21 minutes (in 7 minute increments), I baked the semolina in baking sheets, at 350°F (180°C). I then baked it for 2 increments of 12 minutes (24 minutes). Between increments, I gently stirred the rava with a slotted spoon.
A couple of obvious changes happened. Firstly, the rava smelled wonderful and roasted as time went on. For another, in the initial stages, the rava tended to clump a bit. This is normal. There's a bit of residual moisture in the rava from the surrounding air. When the whole thing is roasted to perfection, the moisture is driven out, and the rava becomes free flowing again. Initially, just stir through the lumps. It'll all work out. Finally, the rava became a light golden brown. Don't take it much further than that. That's about where you want it to be.
The best part of this method is that at the end of the first 21 minutes, I was able to prep my ingredients for the actual uppuma, and get them on the stove. This meant that I was using my time efficiently.
All said and done, yesterday's project took about an hour from start to finish. However, I now have a jar of pre roasted rava, with which to cook future meals very quickly. Once the rava is roasted, the actual uppuma itself takes about 10 minutes.
Why not cook the uppuma without roasting the semolina? Because then the uppuma will be a big gross clump of disgusting, and not be fluffy and delicious.
Once more, totally not speaking from experience.