Cook the potatoes. Peel and cube the sweet potatoes. Add them to a large pot and add enough water to cover them by several inches. Bring the ingredients to a boil, then decrease the heat, so they are simmering. Cover the pot and cook the potatoes until they are very tender when pierced with a fork.
Cool and mash the potatoes. When the potatoes are done, drain them and allow them to cool a little. Transfer them to a large bowl. Sprinkle the paprika and salt over the potatoes. Then use a potato masher to mash them smooth. You can also use a hand beater or food processor to mash them.
Make the lentil filling. Heat a large skillet or large saucepan to medium heat. Add the onions, celery, and carrots. Cook them for 5 minutes until they soften and get translucent.
Add the garlic and stir for 30 seconds, then add the Marmite. Immediately add the red wine and stir it to deglaze the bottom of the pot.
Add the tomatoes, thyme, and Worcestershire sauce. Stir the bottom of the pot to release any stuck-on bits of ingredients.
Stir in the red lentils and bring the pot to simmer. Cover the pot, leaving an air vent. Simmer the lentils for about 15 minutes or until they are tender and get creamy. If the lentils start to dry before they are tender, add a bit of vegetable broth or water.
Taste the filling and add salt and/or black pepper if desired.
Preheat the oven and make the pie. Preheat the oven to grill. See the notes for baking shepherd’s pie from cold. Transfer the lentil mixture to a casserole dish (9 x 13 inches). Spread the filling evenly. Use the back of a spoon to spread the mashed sweet potatoes over the top evenly.
Grill. Place the casserole dish in the oven and grill for 15 minutes until the top is golden brown.
Set up and serve. Remove the pie from the oven and let it sit for 5 minutes. Then serve it.
Shepherd’s pie can be made ahead of time and baked cold. To do this, preheat the oven to 350 degrees (180 C.). Bake for 45 minutes. If you want to brown the top, set the oven on grill (broil) for the last 10 minutes.
To make 2 tablespoons of vegan Worcestershire sauce, use 3 teaspoons soy sauce, 1 ¼ teaspoon lemon juice, 1 ¼ teaspoon maple syrup (or another vegan sweetener), and ½ teaspoon hot sauce, like Tabasco. You can also use miso paste or liquid amino acids.
Keywords: vegan sweet potato shepherd's pie, plant-based shepherds pie