Mix oil, sugar and egg yolk and beat until soft. Beat egg white separately until it thickens. Add rose-water, flour, and egg-white to the mix and stir well. Dissolve saffron in a bit of hot water and add to the mix. Pour the mix in a plastic bag and keep in the refrigerator for 24 hours.
Make small balls out of the mix. Press in on each ball to create a concavity. Add a bit of crushed almonds and sugar. Fill in the concavity with a bit of the mix to create a round ball again. Stick some pistachio slices on the balls. Cook in the oven at 300F for 20 to 25 minutes. Colour should not change much.