- Lightly oil a 13- by 9- by 2-inch baking dish. Whisk the first 8 ingredients together in bowl to blend.
- Cut seitan into twelve 1/2- to 3/4-inch-thick triangles. Dip triangles in the marinade and arrange in the prepared dish, overlapping slightly. Pour remaining marinade over seitan. Cover and refrigerate at least 1 hour and up to 1 day.
- Preheat oven to 425 degrees. Bake seitan triangles uncovered for about 15 minutes, turning once, until marinade is absorbed and seitan triangles are heated through and golden brown.
- Transfer seitan triangles to plates to serve.
Serve with Golden Gravy, Garlic Mashed Potatoes and Roasted Winter Vegetables.