To prepare the wild mushroom marinara, in a large, wide heavy saucepan or large, deep sauté pan over medium-high heat, warm the olive oil. Add the onions, carrots, celery and 1/2 teaspoon salt and cook, stirring occasionally, until soft, fragrant and lightly golden, 10 to 15 minutes. 

Meanwhile, in a small saucepan over medium-high heat, rehydrate the dried mushrooms in 2 cups water. Let stand for 5 to 7 minutes, then drain, reserving the soaking liquid. Chop the mushrooms.

Add the garlic to the onion mixture and cook, stirring, for about 30 seconds (don't let the garlic brown). Add the tomatoes, basil and parsley bring to a simmer. Reduce the heat to maintain a low simmer and cook uncovered, stirring occasionally, until the sauce is reduced, glistening with oil and concentrated in flavor. 

Add the rehydrated mushrooms and about 1/4 cup of the mushroom soaking liquid. Continue simmering for 30 to 40 minutes, tasting as you go. Add the red pepper flakes, then taste, adding more of the mushroom soaking liquid if you want more of that flavor. Taste and adjust the flavor balance if needed with sugar, more salt, black pepper and lemon juice. Makes about 6 cups sauce.

To prepare the mushroom cannelloni, in a large sauté pan over medium-high heat, melt 1 tablespoon of the butter. Add the onion and garlic and cook, stirring frequently, until limp but not browned. Add 1/4 teaspoon salt and cook, stirring occasionally, for 5 to 7 minutes. Transfer the onion mixture to a bowl.

In the same pan over medium-high heat, melt the remaining 1 1/2 tablespoons butter. Add the mushrooms, 1 teaspoon salt and 1/4 teaspoon black pepper and cook, stirring occasionally, for about 7 minutes. Add the wine and simmer until almost evaporated. Remove from the heat. Add the onion mixture, egg yolks, ricotta, Parmesan, mascarpone and nutmeg. Mix well and set aside to cool. Season with 1/2 teaspoon salt.

Preheat the oven to 425°F. Spray a 9-by-13-inch baking dish or a half sheet pan with nonstick coating spray.

Scoop about 1/3 cup of the filling into each egg roll wrapper and roll each wrapper to enclose the filling. Place, seam side down, in the prepared baking dish, spacing the cannelloni slightly apart. Place the Teleme cheese on the cannelloni to cover. Spoon the mushroom marinara sauce over the cannelloni, adding an equal amount to each one.

Bake uncovered until the sauce is bubbling and the cannelloni are hot in the center, 10 to 15 minutes. Use a wide spatula, transfer the cannelloni to plates, spooning any extra sauce around them. Garnish with the parsley and serve.