Whisk together flour and ¾ teaspoon salt. Add water and 3 tablespoons oil and mix until a dough comes together. Turn dough out onto a lightly floured surface and knead a few times until smooth and cohesive.

Divide dough into two equal halves; set aside.

Combine sweet potato purée, cashew cream, nutritional yeast, 2 teaspoons thyme, garlic, red pepper flakes, nutmeg, and remaining ¼ teaspoon salt; set aside.

Bring a large pot of water to a boil and coat a sheet pan with nonstick spray.

Roll each piece of dough into a long rectangle, about ⅛-inch thick. Trim dough rectangles to loosely match in size. On one dough rectangle, using a tablespoon measure, spoon sweet potato filling 1-inch apart down rectangle in two rows.

Season boiling water with salt, then add 4–5 ravioli to boiling water and cook until ravioli float to top, 3–4 minutes. Using a spider or slotted spoon, transfer ravioli to prepared sheet pan.

Heat remaining 3 tablespoons oil over medium high heat in a sauté pan until shimmering. Add mushrooms and shallots and cook until mushrooms are golden brown, about 10 minutes. Increase heat to high and cook until deep golden brown, 1–2 minutes.

Off heat, stir in watercress, hazelnuts, lemon juice and remaining 1 tablespoon thyme. Add ravioli, drizzle with additional olive oil and serve.