In a large pot, combine the lentils and vegetable broth. Bring to a boil, then reduce heat and simmer for 20-25 minutes or until lentils are tender. Drain any excess liquid and set aside.
In a separate large skillet, heat the olive oil over medium heat. Add the onion and garlic, sauté until fragrant.
Add carrots and mushrooms, cook until softened.
Stir in the cooked lentils, TVP, dried thyme, dried rosemary, paprika, tomato paste, and soy sauce. Cook for another 5 minutes.
In a small bowl, whisk together the flour and water to create a slurry. Pour the slurry into the skillet and mix well. Allow the mixture to thicken.
Season with salt and pepper to taste.
Preheat the oven to 400°F (200°C).
Transfer the lentil and vegetable mixture to a baking dish. Top with mashed potatoes, spreading them evenly over the mixture.
Bake for 25-30 minutes or until the mashed potatoes are lightly golden.
Serve hot with steamed green veggies on the side.
