Soak rice in hot water for 15 minutes.
Rinse in cold water until the water runs clear; then drain and set aside.
Use a medium to large saucepan to heat the oil.
Sauté the whole garlic and chopped onion until they soften, adding a bit of salt as well.
Simultaneously, use another saucepan to heat the stock and saffron.
When the onions are completely soft, remove the garlic from the pan and add the previously drained rice.
Sauté for a minute to coat the rice with oil, then pour the hot stock (with saffron).
Cover with a lid, set to high and bring to a boil.
Lower the heat and simmer for about 17 minutes. Taste and adjust the seasoning by adding more salt as needed.
Add the thawed green peas, mix, and cook for an additional 3 minutes.
Place the lid back on, remove the pan from the heat, and set it aside for 5 minutes.
Use a fork to loosen your arroz amarillo -- serve and enjoy!