Preparation:

Step 1: Prepare the Potatoes

Place the peeled and chopped potatoes in a large pot of salted water. Bring to a boil and cook for 15-20 minutes or until the potatoes are tender when pierced with a fork.

Step 2: Prepare the Filling

While the potatoes are cooking, heat a large skillet over medium heat and add a drizzle of olive oil. Sauté the onions and garlic for 3-4 minutes until softened and fragrant. Add the diced carrots, celery, and mushrooms, and cook for another 5 minutes, stirring occasionally, until the vegetables start to soften and the mushrooms release their moisture.

Step 3: Add Lentils and Seasonings

Add the lentils, tomato paste, soy sauce, thyme, rosemary, and smoked paprika to the skillet. Stir to combine and coat the ingredients with the seasonings. Cook for another 1-2 minutes to allow the flavors to meld.

Step 4: Add Liquids and Simmer

Pour in the vegetable broth and canned tomatoes, stirring well to combine. Bring the mixture to a simmer, then reduce the heat to low, cover, and cook for 20-25 minutes until the lentils are tender, and the filling has thickened. Stir occasionally to prevent sticking, and add a bit more broth if the mixture becomes too dry. Once done, season with salt and pepper to taste and stir in the frozen peas.

Step 5: Mash the Potatoes

Drain the cooked potatoes and transfer them to a large bowl. Add vegan butter and plant-based milk, mashing the potatoes until smooth and creamy. Season with salt, pepper, and nutritional yeast (if using) for added flavor.

Step 6: Assemble the Cottage Pie

Preheat your oven to 400°F (200°C). In a baking dish, spread the lentil and vegetable filling evenly across the bottom. Gently spoon the mashed potatoes over the filling, smoothing them out with a spatula to create an even layer. Use a fork to create small ridges on the top of the potatoes, which will crisp up beautifully in the oven.

Step 7: Bake

Place the assembled pie in the preheated oven and bake for 20-25 minutes or until the mashed potatoes are golden and slightly crisp around the edges. For extra crispness, turn on the broiler for the last 2-3 minutes, watching closely to avoid burning.