Melt ghee/butter in a pan and roast suji on low heat for 20 mins or until it smells nutty and turns light brown then add the nuts and turn off the stove.
Once Suji has roasted, in a separate saucepan, dissolve sugar in water + cardamom powder and let it come to a boil till it reaches just about a one-thread consistency (this will happen VERY quickly once the syrup comes to a boil.) Once it starts to boil, add rosewater and yellow food color. Let the syrup continue to boil for no more than 10 seconds and then pour into the suji.
If you are letting the suji set in the same pan, then quickly work to flatten it and smooth the top with the help of a rubber or wooden spatula. If you are using another serving tray, you will have to work VERY fast. As soon as you pour in the syrup, quickly mix it with the suji and then dump into the serving tray and flatten quickly.
Top with more nuts and press gently. The suji will have already firmed up. If its still a bit wet, don't worry. It will set in the next 20 mins. Score the suji all the way through by running perpendicular lines in the shape of diamonds.
Once fully set, slice a spatula under them and separate the Suji Tukdi very gently.