Preheat the oven to 375°. Dust off any flour or cornmeal on the pasta, and lay it in a single layer on a cookie sheet. Toast in the oven till quite brown, doing as many batches as you need to, depending on how many cookie sheet you have. Cool
Rinse the mushrooms, or rub off any dirt. Melt the butter and oil into a heavy skillet or cast iron pan, and add the onions and garlic. Cook until softened, and add the thyme. Mix well, then add the mushrooms. Cook until softened, and add the wine and tomato paste. Season with salt and pepper, and continue to cook over medium heat until thick.
Heat a large pot of water, and salt it. Break up the toasted pasta and toss it in. Cook till al dente, and drain in a colander. Melt half a stick of butter in the pot, add the pasta, and 1/3 cup parmesan, and toss well.
Arrange the pasta on a platter, spoon the ragoût over, and serve, with bread and butter and a rough red wine.