Preparation

• First, make the filling: Coat a large skillet with olive oil set over medium-high heat. Add the onions and saute until golden brown. Add the mushrooms and saute until their liquid bubbles. Season with fresh thyme, salt and pepper. Transfer to a colander and drain, pressing gently to remove all liquid. Place ½ cup of mushrooms in a bowl and set aside. Place the rest of the mushrooms in a medium-size bowl for the filling, and stir in the ricotta and Parmigiano Reggiano. Set the filling aside.

• Next, fill the pasta: Lay out the pasta squares on a clean work surface, adding a touch of semolina or all-purpose flour if they begin to stick. Place 1 tablespoon of the filling into the center of each square. Rub warm water on two adjacent sides of each square. Fold the squares into triangles and seal.

• Now, make the sage-brown butter sauce: Cook the butter in a saute pan over medium-high heat. When it starts to bubble, skim the foam off the top and reduce the heat to low. Let simmer until the butter starts to smoke and turn brown, about 20 minutes.

• Remove the pan from heat and very slowly and gently stir in the sage. Once the sage is fully incorporated, stir in the stock. Remove from heat and keep warm, or keep over very low heat.

• Fill a pot with water and 1 tablespoon of salt, and set over medium-high heat. Bring to a boil. Working in batches if necessary, add the ravioli to the water. When the pasta floats to the top, remove with a slotted spoon and set aside.

• Add the reserved sauteed mushrooms and the pasta to the pan with the sage-brown butter sauce and toss with the sauce.

• Serve immediately.