Risotto with Pancetta and Mushrooms

4 paper-thin slices of pancetta or bacon (about 2 ounces)
1/2 tablespoon extra virgin olive oil
1/2 pound mixed mushrooms, inch as field and Portobellos, thickly sliced
2 tablespoons unsalted butter
1/2 teaspoon finely chopped tarragon
2 1/2 cups light chicken stock
1/2 garlic clove, minced
1/2 shallot, minced
3/4 cup arborio rice
1/4 cup freshly grated Parmigiano-Reggiano cheese (2 ounces), plus shavings, for garnish
1 tablespoon heavy cream
ground white pepper and sea salt, to taste

Preheat the broiler. Arrange the pancetta slices on a baking sheet in a single layer and broil for 1 to 2 minutes, or until golden and sizzling. Drain on paper towels, then crumble.
In a large nonstick skillet, heat the oil. Add the mushrooms, season with salt and cook over high heat, stirring just until they exude their juices, 3 to 4 minutes. Transfer the mushrooms and their liquid to a strainer set over a bowl and press lightly on the mushrooms; reserve the liquid. Wipe out the skillet and add 1/2 tablespoon of the butter. Return the mushrooms to the .skillet and cook, stirring, until tender and just beginning to brown, about 3 minutes. Add the Tarragon, cover and keep warm

In a medium saucepan, combine the stock with the reserved mushroom liquid and bring to a simmer, then keep warm over low heat. In a large, deep nonstick skillet, melt 1/2 tablespoon of the butter. Add the garlic and cook over moderate heat until fragrant. Add the shallot and cook until softened but not browned, 3 to 4 minutes. Add the rice and stir until the grains are thoroughly coated with butter.

Add 1 cup of the hot stock to the pan and cook, stirring constantly, until the rice has absorbed most of the stock, to 2 minutes. Continue to cook the risotto, adding the stock 1 cup at a time, and stirring constantly between additions until it is absorbed. Cook the risotto until it has a creamy, porridge-like consistency, about 20 minutes.

Remove the risotto from the heat and stir in the grated Parmigiano~Reggiano,mushrooms, the cream and the remaining I tablespoon of butter. Season with salt and white pepper and transfer to warm soup plates. Garnish with the pancetta and shavings of Parmigiano-Reggiano. Serve immediately.