Step 1

Soak dry green lentils overnight in water. Melt the butter in a large, heavy bottomed pan over medium-high heat. Add sliced the onion and sauté for 4-5 minutes until translucent. Add the button mushrooms to the pan and sauté for 5 minutes until they are brown and begin to release some water. Add the garlic and sauté for 2-3 minutes until fragrant. Drain the green lentils if there is any water left and add them to the pan. Add the tomato paste and tamari and stir until everything is combined. Add the stock and sliced carrots, stir and lower the heat to medium. Leave the pot uncovered and allow everything to simmer together for about 45 minutes, stirring regularly. The lentils will be finished when most of the stock has been absorbed or has evaporated and the lentils begin to break apart. Taste and season with salt and pepper as needed. Turn the heat off and stir in the corn and peas.

Step 3

While the lentils are cooking, prepare the potatoes and the gravy.

Step 5

To a medium saucepan add the heavy cream, milk, rosemary, sweet and russet potatoes and season with salt and pepper. Bring the pot to a boil and then reduce to a simmer. Allow the potatoes to simmer for 5-8 minutes or until they are soft but not falling apart (keep an eye on them). Drain the cream and milk from the pot and set aside.

Step 7

To make the gravy, melt the unsalted butter in a medium saucepan over medium-high heat. Add the tomato paste and tamari and whisk everything together. Sprinkle in the flour and whisk for 2-3 minutes until combined and slightly cooked. Add heavy cream and mushroom stock and continue whisking until the gravy begins to bubble and thicken. Taste and season with salt and pepper as needed. Turn off the heat and set aside.

Step 9

Preheat the oven to 400F degrees. Stir the gravy into the cooked lentils and vegetables and tip everything into a large baking dish. Carefully arrange the par-cooked sweet and russet potato coins on the top of the dish in an alternating fashion. Sprinkle the potatoes with grated parmesan and top with a sprig or two of fresh rosemary. Transfer the baking dish to the oven and bake for 25-35 minutes or until everything has heated through and the potatoes are crispy. Allow to cool for 5 minutes before serving.