Step 1

Begin by making the mashed potatoes. Wash, peel, and chop the potatoes into roughly 1" cubes. In a large stockpot bring 6 cups of water to boil. Add cubed potatoes and boil until soft, about 15 minutes. Time will depend on how large your pieces are. Potatoes are done when they are easily pierced with a fork. Drain the water through a colander and rinse under cold water until the potatoes have cooled enough to handle. Lightly mash the potatoes with a potato masher. Once most of the big chunks have broken down, add the remaining ingredients and mix together until well incorporated and the potatoes are light and fluffy. Set aside.

Step 2

Preheat your oven to 400 F. Spray a 3-quart casserole dish and set aside.

Step 3

In a large skillet, heat olive oil over medium heat. Add onions and garlic and sauté for 5 minutes, until onions are translucent and fragrant. Add the carrots and mushrooms and sauté for an additional 2 minutes, until the mushrooms have started to release their juices. Stir in spices and salt until fully coated. Add the lentils, vegetable broth, and tomato paste. Bring to a boil, reduce heat to a simmer, and cover. Cook for 30-40 minutes until the lentils are cooked all the way through and all the liquid has absorbed. Stir in the peas.

Step 4

Transfer the lentil/vegetable mixture to your prepared casserole dish. Top with the mashed potatoes. Smooth evenly with a spoon or offset spatula. Drizzle with a little extra olive oil and sprinkle with salt and pepper.

Step 5

Cook for 10-15 minutes until the potatoes have turned golden brown and the liquid underneath is boiling over. Remove from the oven and let cool 10 minutes before serving.