The best diet is the manufactured packaged food, as it has all the nutritions required. What you need to do is look for a good company one and or also speak to good breeders there as to which one is the best.
For example in India we get imported from France Royal Canin, which is very good and you get gaint puppy, giant Jr and Gaint adult based on the age of the pup. Suppliments are also advisable at times, but after consulting your vet. We also get Eukonoba (check the spelling) and that is from America and it is nice also, but suppliments would be advisable. When I suppliments I mean calcium and vitamins.
Dogs/ pups require certain amounts of proteims, carbo, etc for growth and also to maintain good health in adult dogs, hence desi foods cannot give you the right amount.
Otherwise I have had a Rottweiler who I fed solely on Milk and Roti and he did really well and was also a champion, but then I have had one fed on Royal Canin and Eukonoba and it too did well and became a champion. But I do not advise milk and roti. On the otherhand you can also make a stock/ soup with vegetable, such as potatoes, carrot, etc and then add roti and feed. If you want non veg then prepare it like the veg one but add meat to it and cook soup and add roti.
The problem with the above too is that if the roti is not cooked properly then your dog can get a bad stomach etc. as you have to make so many rotis and it not easy. Also the soup has to be cooked well otherwise the same problem. Meat not well cooked can also cause a lot of problems like worms, skin problems etc.
I good guide to feeding a Rottweiler pup is as much as its size of the head, but then it differs based on it size also.
I will strongly advise the manufactured food due to right nutritional value and also guide as to how much to feed. Please also start training and do not spoil your dog or tie it up. All the best.