Step 1

In a large Dutch oven, heat 2 Tbs. of the oil over high heat. Once the oil is shimmering, add half of the mushrooms and cook until lightly browned, about 3 minutes. Repeat with 2 Tbs. oil and remaining mushrooms. Transfer to a bowl and set aside.

Step 2

Add the remaining 1/4 cup oil to the pan, and heat over medium-high until smoking. Add onions and cook, covered, until light brown, about 10 minutes, stirring occasionally. Add 1/2 cup water to the pan and cook, uncovered, stirring occasionally, until all the water has evaporated and onions look more browned, about 5 minutes. Carefully add the wine, and stir, scraping up any browned bits on the bottom of the pan. Cook until the wine is evaporated, about 2 minutes.

Step 3

Add the garlic, thyme, pasta, 8 cups water, and 1 tsp. salt. Bring to a boil over high heat. Reduce heat to medium-high and cook, uncovered, stirring frequently until the pasta appears creamy and has absorbed most of the water, 10 to 12 minutes.

Step 4

Drain any liquid from the mushrooms. Add the mushrooms to pan, and cook, uncovered, until all the water has absorbed and the pasta has doubled in size and cooked to al dente, about 4 minutes. Remove from the heat. Remove and discard the thyme sprigs. Add the Parmigiano, and stir to combine. Season to taste with salt and pepper.

Step 5

Divide among pasta bowls, garnish with additional Parmigiano and the parsley, and serve immediately.