Cook the potatoes: Boil in salted water for 15 minutes until fork-tender.
Mash like you mean it: Drain and mash with plant milk, butter, garlic powder, and salt. Set aside.
Sauté the base: In a skillet, heat olive oil. Add onion, carrot, and celery. Cook 5–7 minutes until soft.
Flavor bomb: Stir in garlic, tomato paste, soy sauce, thyme, cumin, salt, and pepper. Let it sizzle for 2 minutes.
Add lentils & broth: Pour in lentils and broth. Simmer uncovered for 20 minutes until lentils are soft and mix thickens.
Finish the filling: Stir in frozen peas and cook for 2 more minutes.
Layer it up: Pour lentil mixture into baking dish. Spread mashed potatoes over top evenly.
Bake it: Broil for 5–7 minutes until top gets golden. Try not to drool while it crisps.
Cool slightly & serve: Let it sit for 10 minutes (if you can wait), then dig in.