Directions:
Preheat the oven to 400°F (200°C).
In a pot, combine 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.
While lentils cook, heat olive oil in a large skillet over medium heat. Add the onion, garlic, carrot, and celery, and sauté for 5 minutes, or until softened.
Add mushrooms, thyme, rosemary, salt, and pepper, and cook for another 5 minutes. Stir in tomato paste and frozen peas, then add the cooked lentils, mixing well.
In another pot, boil the sweet potato until soft, about 10-15 minutes. Drain and mash with non-dairy milk and vegan butter or olive oil until smooth and creamy. Add salt and pepper to taste.
Spread the lentil mixture in an even layer in a baking dish. Spoon the mashed sweet potato over the top, spreading it evenly.
Bake for 20 minutes or until the sweet potato is golden and slightly crispy on top.