Authentic shepherd's pie is a comfort food classic, but there's no room in my diet or grocery budget for a heavy dish of ground lamb or beef and buttery potatoes, except as an occasional treat. Lentils and mushrooms are more my speed, and sweet potatoes, roasted until creamy-soft, need just a little salt and pepper to be a flavorful topping.
This recipe uses one unusual ingredient: steel cut oats! The dry oats, cooked and drained with the lentils, release just enough starch to bind the filling into a creamy, mushroomy mass rather than a loose scattering of lentils and vegetables. It also adds a texture somewhat like ground meat, but isn't noticeable unless you know to look for it, so your guests will have no idea their dinner includes a nutritious breakfast staple.
Speaking of guests, this recipe is an ideal dinner party dish for vegan or vegetarian eaters. It's hearty, full of umami flavor, and looks and feels like a proper main dish, rather than a vegetable side dish that received a promotion. But that doesn't mean it's only for those who can't eat the meat version — I've served it to omnivorous guests and my meat-loving husband with great success.
Lentil, Mushroom & Sweet Potato Shepherd's Pie
Makes 6 servings
5 medium sweet potatoes, scrubbed
1 cup brown or green lentils, washed and picked over
3/4 cup dry steel cut oats
1 bay leaf
1 teaspoon salt
1 tablespoon olive oil
1 pound cremini mushrooms, divided
1 onion, chopped
1 carrot, chopped
1 celery stalk, chopped
1 garlic clove, minced
3/4 cup low-sodium vegetable stock
1/4 cup red wine
1 tablespoon tomato paste
1 tablespoon soy sauce or tamari
2 teaspoons smoked paprika
1/4 cup chopped fresh parsley
Preheat the oven to 400°F. Prick each sweet potato several times with a fork and place on a baking sheet. Roast for 45 minutes to 1 hour, or until very soft to the touch. Set aside to cool.
In a medium pot, combine the lentils, oats, bay leaf and salt with 5 cups of water. Bring to a boil and lower heat. Simmer uncovered for 15-20 minutes or until lentils are soft but not mushy, stirring occasionally to keep the oats from sticking to the bottom of the pot. Discard bay leaf and drain mixture into a colander or sieve.
While the lentils and oats are cooking, finely chop half of the mushrooms and set aside. Cut the remaining mushrooms into quarters. Warm the olive oil in a large pot over medium-high heat. Add the quartered mushrooms and a pinch of salt and cook until browned and soft. Add the chopped mushrooms, onion, carrot, celery and garlic and cook, stirring occasionally, until onions are soft and translucent. Lower heat to medium and add the lentil and oat mixture, followed by the vegetable stock, wine, tomato paste, soy sauce, paprika, and parsley. Taste and add salt if needed. Simmer mixture for 5 minutes. Remove from heat and add a few grinds of black pepper.
Preheat oven to 350°F. Peel sweet potatoes with your hands and place in a medium bowl. Use a fork to mash them into a smooth paste and season to taste with salt and pepper.
Evenly spread the lentil mixture into a 9x13-inch baking dish. (For thicker layers, use a 9x9-inch pan.) Spoon the sweet potato mixture on top and smooth with a spatula. Bake for 30 minutes, or until the filling is bubbling at the edges.
• Both the filling and the roasted sweet potatoes can be made ahead and refrigerated up to 2 days before assembling and baking.
• This recipe freezes well; after assembling, cover and freeze. Thaw overnight in the refrigerator and bake uncovered at 350°F for 35-45 minutes, or until filling is bubbling at the edges.
• Leftover mashed potatoes can be used in place of the sweet potatoes.
• Use tamari in place of soy sauce and double-check that you are using gluten-free oats if serving this to gluten-free guests.