A favourite cosy dish all winter long, this vegetarian sweet potato cottage pie has a wonderfully textural lentil and mushroom base. With red wine and smoked paprika, it’s deeply savoury and a nice contrast with the sweet potato topping.
You’ll have to make baked sweet potatoes and turn them into mashed sweet potatoes for the topping here. If you want something a little more classic you can make a lentil cottage pie or use a mix of sweet and regular potatoes. This recipe is adapted from my vegan mushroom and pumpkin shepherd’s pie.
Ingredients

Ingredient Notes and Substitutions
- Mushrooms: any type of mushroom will do. Use buttons as pictured for the easiest option, but penny buns would be excellent if you can find them, as would parasols.
- Sweet potato: make sure to use sweet potato, not yam (sometimes sweet potatoes are mislabeled as yams). The latter have a thicker, brown skin that looks a bit like a mushroom, and white flesh.
- Lentils: use brown, green, or black lentils, but not red.
- Vegetable broth: if you don’t have any, you can use water and season well, but this is one dish where a good broth will make a difference.
- Peas: I always use frozen peas. You can sub frozen corn or leave it out altogether.
- Starch: you can use corn or potato starch in the same quantities, or 1.5x the amount of arrowroot, or 2x the amount of plain flour.
- Red wine: if you don’t use wine, substitute 2 teaspoons balsamic vinegar OR 1 tablespoon tomato paste (be sure to fry it out with the garlic) and make up the rest with water or broth.
Step by Step
You can find a longer guide on mashed sweet potatoes here, but this is outlined in the recipe card as well. (That also gets into why baked potatoes are used rather than boiled.)

Step 1: fry the mushrooms over medium, stirring only occasionally, then add the onions.
Step 2: cook until the onions are translucent, then stir in the garlic, herbs, and spices.
Step 3: deglaze with the wine, stirring to release any stuck bits from the pot.
Step 4: add the broth and increase the heat.

Step 5: once boiling, stir in the lentils and cook for about 20 minutes.
Step 6: stir in the starch and water mixture while still simmering to thicken the mixture.
Step 7: top with the peas and sweet potato mash.
Step 8: bake for 10-15 minutes and serve hot.
Recipe Notes
That bit of bubbling up around the edges of the dish is how you’ll check to see if the pie is done baking. While it doesn’t actually need to bake – the elements are already cooked – it’s nice for a couple reasons. One, you can prepare in advance and simply heat before serving. Two, it’s simply more attractive to serve in a single dish together.
If you would like to prepare in advance, cook the filling and topping, then assemble in the baking dish and cool fully. Refrigerate for up to 24 hours, well covered, before baking as instructed.
How to Store
Storage: keep leftovers in a sealed container in the refrigerator for up to three days. I recommend reheating in the oven as it tends to stick when reheated on the stovetop.
Freezing: transfer fully cooled pie to an airtight container and freeze for up to two months. Thaw in the refrigerator before reheating as usual.
Expert Tips
- Bake in the pot: if this is for a casual family dinner, there’s no need to transfer the filling to another baking dish if the pot you’re using is oven-safe. I often add the topping right to the pot and bake in that rather than using a special baking dish (see pumpkin shepherd’s pie).
- Sear the mushrooms: for the best texture and flavour, it’s key to cook the mushrooms before you add anything else, and make sure all the water has evaporated from them. Soggy mushrooms are unpleasant and won’t give the meaty texture we’re looking for.
- Season to taste: make sure to check both the base and the topping for seasoning before assembling and baking. While you can add salt after, you’d have to mix everything together, and it’s not as nice.
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Vegetarian Sweet Potato Cottage Pie
Ingredients
- 1 tablespoon olive oil
- 250 grams button mushrooms diced
- 1 medium onion finely chopped
- 2 cloves garlic minced
- 1 sprig rosemary leaves minced (about 1 tablespoon)
- 1 teaspoon sea salt to taste
- ½ teaspoon black pepper freshly ground, to taste
- ¼ teaspoon smoked paprika
- 50 ml dry red wine*
- 500 ml vegetable broth
- 150 grams brown lentils
- 1 tablespoon thyme leaves finely chopped
Thickener
- 1 tablespoon water
- 2 teaspoons corn starch
Topping
- 1 batch mashed sweet potatoes
- 150 grams frozen peas
Instructions
- Start by making the sweet potatoes. Cook two sweet potatoes, halved and cut-side down, on a baking sheet in a 200°C (400°F) oven for about 30 minutes. While they're baking, prepare the lentil base.1 batch mashed sweet potatoes
- Heat the oil in a large heavy-bottom pot over medium. Once the pot is hot, add the mushrooms. Cook, stirring as infrequently as possible, until browned and any water has evaporated.1 tablespoon olive oil, 250 grams button mushrooms
- Stir in the onions and cook for another five minutes, stirring occasionally, until softened. Add the garlic, herbs, and spices, and cook for another minute.1 medium onion, 2 cloves garlic, 1 sprig rosemary leaves, 1 teaspoon sea salt, ½ teaspoon black pepper, ¼ teaspoon smoked paprika
- Add the red wine and stir to release anything stuck to the bottom of the pot, then pour in the vegetable broth. Cover the pot and bring to a low boil.50 ml dry red wine*, 500 ml vegetable broth
- Once the broth is boiling, stir in the lentils. Turn the heat down to simmer and cook, covered, for 15-20 minutes, or until the lentils are softened. Stir in the thyme.150 grams brown lentils, 1 tablespoon thyme leaves
- While the lentil mixture is still simmering, mix the water and starch together in a small bowl. Stir this mixture into the lentils, then simmer for a couple minutes more to thicken.1 tablespoon water, 2 teaspoons corn starch
- Transfer the lentil mixture to a large baking dish and top with the frozen peas. Mix up the baked sweet potatoes with milk, olive oil, and salt, then spread over the pie filling.150 grams frozen peas, 1 batch mashed sweet potatoes
- Bake at 200°C (400°F) for about 10 minutes, or until you see the filling bubbling up around the edges of the dish. Serve hot.
Notes
* For American cup measurements, please click the pink link text above the ingredient list that says ‘American’.
Nutrition
Nutrition is provided as a courtesy and is an estimate. If this information is important to you, please have it verified independently.
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