Bring two cups of water to boil. Add the dried mushrooms and allow them to steep and rehydrate, about 10 minutes. Once ready, use a slotted spoon to scoop out the mushrooms and place in a small bowl to slice alongside the fresh mushrooms, leaving the broth. Add in the remaining 3 cups of stock and bring to a low simmer.

Heat 3 tablespoons olive oil over medium heat in a 4-quart Dutch oven or heavy bottom pot. Add the shallots and leeks and cook until softened, about 3 to 5 minutes. Add the sliced mushrooms, including the porcini mushrooms, along with the salt and ground black pepper, and cook until browned and most of the liquid has evaporated, about 7 minutes. Add the chopped fresh thyme and stir to combine.

Add the garlic and stir for one minute until fragrant. If using the crushed red pepper flakes, add them here and stir. Using a slotted spoon, remove the mushroom mixture to a medium mixing bowl and set aside while you work on the risotto.

To the same pot, add the remaining 3 tablespoons olive oil and add the risotto rice. Stir to coat and lightly toast the rice. Using a ladle, add a ladle of stock at a time, continuously stirring the risotto until most of the liquid is absorbed before adding the next ladle of stock. This process of ladleing stock and stirring the rice will take approximately 30 to 35 minutes until the rice is tender and creamy.

Remove from heat and stir in the parmesan. Add half of the mushroom mixture, reserving the other half for topping the risotto, and stir to combine. Taste and adjust seasoning with a pinch of salt, if desired. Spoon into bowls and serve. Garnish with chopped fresh herbs like parsley or chives.