Packaged seitan, a vegetarian protein made from wheat gluten, is already seasoned, so there’s no need to marinate it before making this warming dish, which pairs well with brown rice. If you can’t find large seitan slabs for cutlets, simply use smaller pieces: dust them in flour, saute, then add to sauce before serving.
1. Coat seitan pieces in flour. Heat oil in large skillet or Dutch oven over medium-high heat. Add seitan, and cook 1 to 2 minutes on each side, pressing pieces down to brown evenly. Remove seitan from skillet, and keep warm.
2. Add mushrooms, onion, and garlic to skillet. Sauté 7 to 10 minutes, or until softened and lightly browned. Whisk together red wine, mustard, and thyme in measuring cup. Add to mushroom mixture; season with salt and pepper, if desired; and cook 2 to 3 minutes, or until slightly thickened. Whisk together cornstarch and vegetable broth in same measuring cup, then add to mushroom mixture. Simmer 2 to 3 minutes, or until thickened, stirring constantly. Place seitan cutlets on plates, top with mushroom sauce, and sprinkle with parsley.