Dice the mushrooms into bite size pieces and sear in the hot olive oil.
Remove with a slotted spoon (keeping the oil in the pan) and reserve.
In the same oil, fry the cloves of whole garlic until tender.
Remove the cloves of garlic and mash in a mortar and pestle with the parsley and saffron too.
Add the vegetables to the pan and sauté in the hot olive oil for two minutes.
Add the garlic paste and the mushrooms (with any juices that came out) back to the pan.
Add one cup of stock and let everything simmer at a low heat for 20 minutes.
Add the two cup of rice and four cups of stock to the pan.
Give everything a stir and bring the mixture to a boil.
As soon as the liquid starts to boil, lower the heat to low and let it cook for 15-20 minutes -- don't stir during this time!
When the rice is al dente and the liquid is absorbed, you're ready to eat!
To get the beloved "socarrat" (the caramelized, lightly burnt crust on the bottom of the paella pan) put a kitchen towel over the finished rice and let it rest for 5 minutes. Then remove the towel and put the paella back on the heat on high. Any liquid at the bottom of the pan will start to evaporate, and when you start to hear a sizzle (in Spain we say it sounds like rain) let it caramelize for about 30 seconds (it should not smell burnt). Remove and serve immediately.