Vegan Mushroom Gravy

Name: Vegan Mushroom Gravy
Ingredients: 1 pound cremini mushrooms, sliced 1/4-inch thick; 1/4 medium onion, sliced 1/4-inch thick; 3 tablespoons extra virgin olive oil; 1/2 teaspoon kosher salt; 1/8 teaspoon freshly ground black pepper; 1 teaspoon dried thyme; 1/4 cup all-purpose flour; 3 to 4 cups unsalted vegetable or mushroom stock; 1 1/2 teaspoons soy sauce; 2 teaspoons red, yellow, or white miso, optional