Keep butter or greaseproof paper and rolling pin ready on a smooth surface.
Take a non stick pan, add ghee and melt for few seconds on a heat. Turn off the heat. Add flour, sugar and milk (add food colour if you're making golden halwa).
Once again turn the heat on and start cooking the mixture, keep stirring continuously on a medium heat and make sure there no lumps are formed.
While on heat keep mixing until the runny content turns to a thick mass.
Turn off the heat and quickly transfer the mixture on a butter paper. Now lay another butter paper on the mixture and quickly start rolling mixture, remove upper paper.
Generously sprinkle almond and pistachio slivers, cardamom seeds and saffron (for golden halwa) and once again lay the paper on the half rolled mixture.
Again roll out the mixture gently and roll to a 2-3 cm thickness and carefully lift off top layered paper.
Let it cool for few minutes, then cut the halwa squares but do not lift or remove.
Allow halwa squares to cool completely (here I keep at least 4-5 hours, depends which country you are in if warm weather it will take more time).
When they are ready you'll see a shiny surface, dry and stiff enough to lift.
Carefully lift each piece and pile interleaved with greaseproof paper between each slice and store in an air tight container.