Mushroom Lentil Shepherd’s Pie (Vegan and Oil-Free)

The mushroom lentil pie is a flavor-packed, plant-based dish that would work well as a main course for a holiday celebration or a comforting, cozy meal for the winter. It's not a quick meal, but it's rich with bold, savory flavors.  

Typically, shepherd's pie uses ground lamb, while cottage pie uses ground beef. In our vegan version, we combine brown lentils with mushrooms cooked with garlic, thyme, and rosemary to give the casserole a meaty texture. The tamari adds a rich umami flavor, finishing with a slightly sweet and tangy balsamic vinegar.

Pair the vegan dinner recipe with a simple salad or mustard maple Brussels sprouts.  For more comforting recipes, try chickpea and butternut curry, orzo veggie soup, or red lentil dahl with coconut milk.

Recipe features

• The recipe is oil-free, vegan/vegetarian, and can be made gluten-free!
• Hearty mushrooms and lentils with soft creamy mashed potatoes!
• Great for a healthy holiday main dish or any time of the year!
• Can be made in advance!

Ingredient notes and substitutions

Please see the recipe card below for a full list of ingredients and exact measurements for the mushroom shepherd's pie. 

Brown lentils - We use brown lentils for this version, but green lentils can be used as well.  Red lentils break down and become creamy, so I wouldn't recommend using those.  Canned lentils can be used instead of dry ones.  Skip the step of boiling with bay leaves, drain the cans, rinse well, and add them to the recipe as if you cooked them.  Substitute 1 cup of uncooked with about 2 ½ cups cooked.  Canned lentils can be salty; adjust the salt in the recipe if needed.

Bay leaves - Two dried bay leaves will flavor the lentils while they cook.  Remove them when you drain the cooked lentils to prevent adding them to the vegetable mixture.

Red onion - A red, white, or yellow onion can be used.

Mushrooms - Mushrooms add a meatiness to the lentil filling.  I opt for cremini or button mushrooms, but most varieties should work.  

Flour - Whole wheat or all-purpose can be used to thicken the lentil filling.  For a gluten-free option, use brown rice flour.

Vegetable broth - I opt for low-sodium vegetable broth/vegetable stock.  If you don't use low-sodium, adjust the salt in the recipe as needed.

Petite diced tomatoes - I prefer the petite diced variety to have smaller bites of tomato.

Tamari - If you can't find tamari, you can substitute low-sodium soy sauce.  Since tamari already has sodium, taste for salt before placing the lentil mixture in the casserole dish. 

Tomato paste - When you add the tomato paste, stir frequently.  The color should darken as it cooks.  It's thick, so it may start to stick to the pan.  If needed, turn down the heat and add a splash of vegetable broth to prevent it from burning.

Balsamic vinegar - Adds a slightly sweet, tangy flavor to balance the savoriness of the dish.  

Yukon gold potatoes - The recipe calls for Yukon gold potatoes, but Russet potatoes can also be used.  Red potatoes don't work well in this dish.  Peel or don't peel the potatoes.

Dairy-free milk - Any dairy-free milk will work.  From personal experience, some shelf-stable plant-based milks are thinner than refrigerated ones.  This may alter how much milk you need to thin out the potatoes.

Nutritional yeast - There is no butter or oil in this recipe, so the nutritional yeast is used to flavor the mashed potatoes.  For more flavor, try adding oil-free roasted garlic to the mashed potatoes.  You can always add vegan butter if you're not oil-free.

Tips

• Cook the veggie mixture with flour and tomato paste for a few minutes until it has thickened. There should be some liquid left, but you should also see the bottom of the pan when you spoon the mixture to the side.
• For oil-free cooking, having a bowl or squeeze bottle of water nearby is helpful.
• Drain the potatoes well, and don't skip steaming the potatoes in the pot.  This helps to prevent watery mashed potatoes.  Make sure the potatoes are warm when spreading them on the lentil mushroom mixture.  Cold mashed potatoes are harder to spread.

Variations

• If you want to make the dish extra special, add roasted garlic to the mashed potatoes. Here's a detailed post on how to roast garlic without oil. Add the roasted garlic cloves to your cooked potatoes before you start to mash them. 
• The potatoes can also be swapped with my recipe for rosemary roasted garlic mashed potatoes with coconut milk or mashed potatoes without butter or oil.
• To make gluten-free shepherd's pie, use gluten-free tamari and brown rice flour instead of whole wheat flour.
• Try canned lentils to save time on the dish; see the lentil notes above for instructions.

Tips to prepare the dish faster

• Use canned lentils instead of cooking them yourself, or cook them ahead of time and store them in the refrigerator until you're ready to prepare the dish.
• Make the entire filling in advance and store it in the refrigerator until you're ready to assemble.  Reheat the prepared lentil mixture before assembling the mushroom lentil pie, then bake as per the instructions below. You may need to add time if the components are cold.

How to make a mushroom lentil shepherd's pie

1. Start this vegan version by chopping all of the veggies and pre-measuring the seasonings. Add the dry lentils, 3 cups of water, and 2 bay leaves to a pot, bring to a boil, then lower to a simmer for 20-25 minutes. The lentils should be tender when done. Drain the lentils, remove the bay leaves, and set the lentils aside.

2. While the lentils are cooking, start the potatoes. Add the chopped potatoes to a large pot, cover with water, and salt generously. Bring to a boil, then lower to a simmer for 15-20 minutes. Cook until the potatoes are fork-tender. 

3. Drain the potatoes, and add them back to their pot.  Set them aside off the burner, keep them covered to steam until you're ready to mash them. I wait to mash the potatoes until I have finished cooking the shepherd's pie filling.

4. I use a large non-stick sauté pan when I cook the vegetables to keep the dish oil-free.  Preheat the pan to medium to medium-high heat, then add the red onion, carrots, mushrooms, and a pinch of salt. Cook until the onions are translucent, the carrots have softened, and the mushrooms have reduced in size and released their liquid, about 7-10 minutes. 

5. Add a tablespoon of water or vegetable broth to the skillet if the veggies are sticking.  Don't use too much because you don't want to boil the vegetables; you want them to brown.  (You can use this method multiple times to alleviate sticking vegetables.). Or cook the veggies in a neutral-tasting oil.

6. Add the minced garlic, thyme, and rosemary, the cook for 1-2 minutes. 

7. Then, add 2 tablespoons of flour and cook for 1 minute, stirring frequently. 

8. Next, stir in the tomato paste and cook for 1-2 minutes, stirring frequently.  For oil-free cooking, add water as needed to deglaze the pan.

9. Now add the vegetable broth and deglaze the pan, scraping off any cooked-on bits with a wooden spoon.  Add the diced tomatoes, tamari, balsamic vinegar, drained cooked lentils, and salt to the vegetable mixture.

10. Bring to a simmer and cook uncovered for about 5 minutes or until the mixture has thickened.  If it gets too dry, add a bit more vegetable broth or water.

11. Taste and season with salt and pepper if needed. Stir in the peas.  They'll thaw when added to the hot lentil mixture.

12. When ready to mash the potatoes, add the milk, nutritional yeast, and salt to the cooked potatoes and mash with a potato masher. Start with 1 cup of milk and mash it into the potatoes.  Add more milk if they're too thick, taste, and adjust for more salt and nutritional yeast.

13. Scoop the vegetable mixture into a 9x13-inch baking dish, then top with potatoes. 

14. Drop mashed potatoes in small clumps.

15. Then spread them out in an even layer. 

16. Then run the back of a fork across the top to get ridges.  

17. Bake uncovered for 20 minutes at 400°F (200 °C).  If you want the top to be more golden brown, broil for an additional 5 minutes.  Keep a close eye on it.

Storage

Refrigerator - Store leftovers in an airtight container in the refrigerator for 4-5 days.

Freezer - Store in the freezer in an airtight container for 2-3 months.  I like to thaw the shepherd's pie before reheating it.  I haven't tested freezing an entire unbaked pie and then baking it, so I can't say for sure how well it would work.  I have only tested small baked portions, which work well.

Reheat - To reheat leftovers in the oven, preheat to 325°F (160°C), cover with aluminum foil, and heat until the filling and potatoes are warmed through.  How long it takes will depend on how much you're warming up.  Alternatively, use the microwave for small batches. 

Serving suggestions

• A simple side salad
• Rustic bread
• Roasted maple dijon Brussels sprouts
• Roasted or steamed root vegetables
• Roasted or steamed broccoli or cauliflower

Related recipes

• Vegan slow cooker quinoa chili 
• Butternut squash chickpea curry soup
• Red lentil dahl with coconut milk

I hope you enjoy the recipe!  If you did, feel free to rate it and leave a comment.