Add a large pot of water to the stove and add 1/2 tsp sea salt. When boiling add the Pappardelle and cook according to package directions.
Add extra virgin olive oil to a heated saute pan over medium heat. When it shimmers, add the onions and shallots. Cook for 4 minutes until they begin to soften.
Add the garlic and the baby bella mushrooms and cook for about 2 minutes.
Then add the butter and stir continuously until it melts. Then add the rest of the mushroom mix and half of the thyme sprigs. Cook for 3-5 minutes. The mushrooms will start to take on a caramelization brown color and soften up nicely.
Add the flour in and mix well. Cook for about 1 minute and then add the white wine and scrape the brown bits on the bottom of the pan.
Let the mix simmer for about 2 minutes and let some of the white wine cook off. Then then add the broth and simmer for 3-5 minutes.
Add the salty pasta water and mix well. Turn off the heat and add the pappardelle.
Serve with additional salt and pepper to taste and more fresh thyme leaves.