Combine sugar and water in a medium saucepan and bring to a gentle boil, Add the saffron, cardamom and the rosewater remove from the heat and set aside to cool.
Place a heavy-bottom pan over medium-low heat and lightly toast the wheat flour for 10-15 minutes, until you smell the toasted aroma. Stirring frequently as the flour burns quickly and makes an unpleasant taste. Flour should slightly change change colour.
Sieve the flour to smooth out any lumps before adding the oil and butter.
Mix in the oil and butter ,stir continuously for about 10 minutes over low heat.
While stirring, gradually pour the sugar syrup into the saucepan using a ladle, until the syrup is fully absorbed and well combined.
Keep stirring until the Halva starts pulling away from the bottom and sides of the pan and comes together as a smooth dough.
Transfer it to a shallow serving platter and smooth out the top with the back of a slightly oily spoon.
Garnish as you desire with almonds, pistachios and rose petals and serve with Persian black tea.
