Heat the oven to 350°F.

• Chop the hazelnuts.

In a sheet pan, spread the nuts in an even layer and toast in the oven until lightly browned, about 5 minutes.

• Remove the stems from the mushrooms.
• With the side of a knife, smash one of the garlic cloves.
• Peel and slice the shallots. Reserve the peels.

In a 4-quart sauce pot, combine the mushroom stems, smashed garlic, shallot peels, 1 sprig thyme and 1 sprig oregano with 2½ cups water. Season with salt and bring to a boil over high heat. Reduce to a simmer, cover and cook until flavorful, about 15 minutes.
While the stock cooks, prepare the sausage.

• Cut the sausage into 1-inch pieces.

In a frying pan over medium heat, warm 1 tablespoon oil until hot but not smoking. Add the sausage and cook until well browned, about 5 minutes. Transfer the sausage to a paper-towel lined plate to drain.
Meanwhile,

• Chop oregano and thyme.
• Cut the mushroom caps into quarters.
• Mince the remaining garlic.

In the same pan used to brown the sausage, cook the shallots and garlic, adding a little more oil if the pan seems dry, over medium-high heat until just beginning to soften, about 2 minutes. Stir in the rice and cook until opaque, about 3 minutes. Add 1/3 cup water or the white wine, if using, and cook until completely absorbed, about 2 minutes. Add the mushroom caps, season with salt, and cook until they begin to soften and release their juices, about 5 minutes. Strain the warm stock directly into the pan (discard the solids). Bring to a boil, reduce to a simmer, cover, and cook, stirring occasionally, until most of the liquid has been absorbed, about 20 minutes. The rice should be just tender and a little bit runny. While the risotto cooks, make the basil oil.

• Chop the basil.

In a small bowl, mix the basil with 1 tablespoon oil and the sherry vinegar. Season with salt.

Remove the risotto from the heat and stir in the sausage, herbs, and parmesan cheese. Transfer to individual bowls and garnish with hazelnuts. Drizzle the basil oil on top.

If the risotto seems be drying out too much while cooking, add a couple tablespoons of water at a time to achieve a creamy consistency.