Preheat oven to 350°F. Spray an 8 x 8" baking dish with nonstick cooking spray.
Rinse ¼ cup dry brown lentils under cool water. Add to a small saucepan with 3/4 cup water. Bring to a boil, then reduce heat to low. Cover and simmer 20 minutes, until lentils are tender but not mushy. Drain any excess water and let cool slightly.
In a food processor, combine the cooked lentils, 1/2 cup water, 2 tablespoons tamari, tomato paste, bouillon, mustard, liquid smoke, chili powder, 1 teaspoon onion powder, 1/2 teaspoon garlic powder, and smoked paprika. Blend until smooth then transfer to a large mixing bowl.
Add the vital wheat gluten, then, working quickly, knead the dough just until combined. The dough will come together almost immediately and have a wet but firm and springy texture.
Turn the dough out onto a clean surface and press into a disc to about 1/2-inch thick. Cut into 4 steak-shaped pieces. (The steaks will expand during the cooking process.)
Arrange the steaks in a single layer in the prepared baking dish.
In a small bowl, whisk together broth, 1 tablespoon tamari, Worcestershire sauce, garlic, and thyme. Pour the mixture around the steaks.
Cover tightly with aluminum foil and bake for 40 minutes. Remove from the oven and let rest, covered, for 10 minutes to finish steaming in residual heat.
In a shallow dish or resealable bag, whisk together the marinade ingredients. Add the warm steaks, turning to coat evenly. Marinate at least 1 hour or up to overnight in the refrigerator.
Preheat a grill pan or oiled outdoor grill to medium heat. Grill each steak for 2–3 minutes per side, basting with leftover marinade for a glossy finish. Serve hot, drizzled with extra marinade.