In a saucepan, combine the sugar and water over medium heat. Stir until the sugar dissolves completely.
Add the tahini to the sugar syrup and mix well.
Cook the mixture over low heat, stirring constantly, until it thickens and starts to pull away from the sides of the pan (about 10-15 minutes).
Add the saffron water and rose water to the mixture and stir to combine.
Remove the pan from the heat and let the halva cool slightly.
Transfer the halva to a serving dish and smooth the top.
Garnish with sliced almonds or pistachios if desired.
Allow the halva to cool completely before serving.
Enjoy!