Heat a large, heavy skillet or dutch oven over medium-high heat then add the olive oil, once the oil is hot and simmering add the mushrooms in a single even layer. Do not over crowd them – cook in two batches if needed. Let the mushrooms cook, undisturbed for 5-7 minutes or until they begin to crisp at the edges and turn golden brown then give them a stir and continue cooking, stirring occasionally until they're soft and golden brown, about 5-7 more minutes. Season with salt and transfer to clean bowl or plate – set aside.
Return the skillet to the stove and turn the heat down to medium. Add the butter, as soon as it melts add the minced shallot and a generous pinch of salt. Cook, stirring frequently, until softened but not browned, about 5 to 7 minutes. In the meantime, in a separate small saucepan bring the chicken stock to a low simmer over medium heat, then reduce heat to lowest setting just to keep warm.
Once the onion is soft and translucent add the garlic and thyme leaves – stir to combine. Next, add the rice. Toast the rice in the butter for 3-5 minutes, stirring continuously then pour in the wine and increase the heat to medium-high to bring the liquid to a simmer. Continue cooking, stirring frequently, until all of the liquid is absorbed into the rice, about 2 minutes. Season with generous pinch of salt.
Begin to gradually add the chicken stock about 1-cup at a time (enough to just barely cover the rice) stirring frequently until absorbed before adding in more. Continue this process over a period of about 15-20 minutes, adding more stock as each previous amount is absorbed. Cook until the rice is al dente and the risotto is creamy and saucy, about 20 minutes total. (If you run out of hot broth, you can use hot water.)
When all of the stock has been used and the rice is creamy and slightly al dente fold in the roasted mushrooms, grated parmesan cheese, heavy cream, truffle oil and lemon juice. Taste and season the risotto with salt and pepper as needed. Divide between bowls, top each bowl with extra grated parmesan cheese, fresh thyme leaves and lemon zest –serve immediately!