Grind the saffron threads in a spice mortar to a powdery texture.
Rinse the rice in a mesh strainer for a few minutes.
In a large pot, bring the water or stock to a boil with the sunflower oil and salt.
Add the saffron and the rice to the pot. Let the mixture come to a boil again. Stir well, then set the heat to low.
Cover the pot with a lid. Let the rice steam over low heat for 20 to 30 minutes, or until rice is tender and little holes have appeared on the surface.
Remove from heat. Leave the rice to rest covered for a few minutes.
Meanwhile, cover the raisins with hot water for a few minutes till they become moist and plump.
Toast the sliced almonds in a skillet over medium low heat, stirring constantly, till golden brown and aromatic.
Drain the raisins. Use a fork to fluff the rice, integrating the drained raisins and toasted almonds as you mix.
Serve warm.
