Heat up the olive oil in a large pot. Add the chopped onion and minced garlic, sauté for 4 minutes. Add the chopped carrots and celery, with seasonings and herbs and cook for about 4 more minutes.
Preheat the oven to 425 degrees. Meanwhile, boil potatoes until fork-tender. Drain potatoes and mash with almond milk, vegan butter, and salt & pepper until creamy.
In a 9 x13” pan add the lentil mixture and then cover the entire top with mashed potatoes. Bake for about 10 minutes until the potatoes start to brown.