ehydrate the porcini mushrooms in a small bowl, with just enough boiling water to cover them. Leave them for 20 minutes and drain, retaining the liquid.
Meanwhile, heat 1tbsp oil in a large pan over a medium heat. Add the onion and garlic and cook until the onion is translucent, about 5 minutes.
Next, add the rice, spices and rehydrated porcinis. Stir and cook for a couple of minutes to combine and toast the rice.
Add porcini water and stock to the pan. Bring to a simmer and wait for this to absorb, stirring occasionally.
Stir often, and add extra water if needed.
After around 15 minutes, all of the liquid should be absorbed and the rice should be cooked.
Add the olive oil and give it one final stir before serving.