Infuse saffron: In a small bowl or cup, add the saffron threads to ¼ cup of hot water. Let it sit for 10-15 minutes, allowing the saffron to infuse the water and releasing its color and flavor.
Rinse and drain the rice: Place the rice in a fine-mesh sieve and rinse under cold running water until the water runs clear. This helps to remove excess starch and prevents the rice from becoming sticky. Drain well and set aside.
Sauté the onions and garlic: In a large skillet or saucepan with a tight-fitting lid, heat the butter or olive oil over medium heat. Add the chopped onion and cook, stirring occasionally, for 5-7 minutes, or until soft and translucent. Add the minced garlic and cook for another 1-2 minutes, until fragrant.
Toast the rice: Add the drained rice to the skillet with the onions and garlic. Cook, stirring constantly, for 2-3 minutes, until the rice is lightly toasted and coated with the butter or oil.
Add the broth, saffron water, and seasonings: Pour the chicken or vegetable broth and the saffron-infused water (including the saffron threads) into the skillet. Stir to combine. Add the salt and black pepper, and stir well.
Cook the rice: Bring the mixture to a boil, then reduce the heat to low, cover with the lid, and simmer for 18-20 minutes, or until the rice is tender and the liquid is absorbed.
Fluff and garnish the rice: When the rice is cooked, remove the skillet from the heat and let it stand, covered, for 5 minutes. Then, using a fork, gently fluff the rice to separate the grains. Sprinkle the chopped parsley or cilantro over the saffron rice. If desired, add toasted slivered almonds, pine nuts, or raisins for additional texture and flavor.
Serve: Transfer the saffron rice to a serving platter or individual plates and serve immediately. Enjoy!