Inspired by the flavors of shepherd's pie, this Lentil Mushroom Bake is a dump & bake recipe that's filled with pantry staples! This vegetarian recipe has only 5 minutes of active time and requires minimal prep.
My newest dump & bake casserole and high protein vegetarian meal recipe is inspired by shepherd's pie!
This Lentil Mushroom Bake only require a few minutes of prep time because the brown lentils cook completely in the oven.
It has a rich, savory base thanks to a combination of pantry staples like balsamic vinegar, dry herbs, and tomato paste.
Unlike classic shepherd's pie, which uses mashed potatoes, this no-boil version uses cubed potatoes, so it's still a balanced meal with veggies, carbs, and protein but doesn't require as much active time.
If you're looking for something a little closer to classic shepherd's pie, check out my Lentil Casserole with Mashed Potatoes instead.
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Recipe summary
- Makes 4-6 servings and freezes well.
- Time: Requires just 5 minutes of active time. The casserole takes about 55 minutes total in the oven, all of which is hands-free time.
- Equipment: To make this recipe you will need a 9x13-inch baking dish that can be tightly covered by an oven-safe lid, foil, or an upside down sheet pan.
- Flavors: Similar to mushroom stew and shepherd's pie, this lentil casserole has a rich balsamic-tomato-herb base.
Ingredients
- Lentils: Choose dry brown lentils. Most bags at the store that just say "lentils" are brown lentils. Red/orange lentils or canned brown lentils do not work here.
- Potatoes: I tested this with russet and Yukon gold potatoes. Both work well, but Yukon gold is a better option if you prefer a potato with a thinner skin.
- Mixed veggies: One 12-ounce frozen mixed vegetable blend. This typically includes peas, carrots, corn, and green beans. The vegetables do not need to be thawed prior to adding to the casserole dish.
- Mushrooms: To keep prep to a minimum I use the pre-sliced baby bella (cremini) mushrooms. If you're not a huge fan of mushrooms, I recommend roughly chopping them so that they disappear into the casserole more.
- Cheese: I used a Swiss and Gruyere blend from my local Kroger (labeled "Alpine Blend") that I think is delicious here. I also use this blend in my Cheesy Broccoli Pasta. Shredded mozzarella is also a good option for something more budget-friendly. To make this recipe dairy-free, simply use your favorite vegan shredded cheese or sprinkle with nutritional yeast.
Step by step photos
- Add all ingredients, including the boiling water or vegetable broth, to a lightly oiled 9x13-inch baking dish.
- Cover tightly with a lid or foil. Bake at 400F for 45-50 minutes. Remove from the oven when the lentils and potatoes are cooked through.
- Top with shredded cheese. Return to the oven for 5 more minutes.
- Remove from the oven when the cheese is melted. Let rest 5 minutes before serving.
Cassidy's tips and variations
- For a more classic take on shepherd's pie, add Garlic Cream Cheese Mashed Potatoes or Mashed Red Potatoes in place of cheese.
- To make this recipe vegan, simply use your favorite vegan shredded cheese. I like Chao shredded cheese and Violife shredded mozzarella.
- If you don't have a lid or foil, you can use an upside down sheet pan to make a tight seal on the casserole dish.
- This recipe can be cut in half to make a smaller batch. Cut all ingredients, including broth, in half. Bake in an 8x8-inch baking dish instead of 9x13-inch.
- I bring water to a boil in a kettle before adding to the casserole because it speeds up cooking time. You can also bring it to a boil on the stove.
- It's okay if you don't add boiling water, it will just add about 15 minutes of cooking time to the lentils, or about 60 minutes covered instead of 45.
Storage notes
- This lentil casserole makes great leftovers. I typically reheat individual portions in the microwave. To reheat the entire casserole, cover tightly with foil or a lid. Bake at 325F for 20-30 minutes.
- The casserole also freezes well. If prepping the entire casserole, I recommend cooking it without the cheese before freezing. Let thaw completely in the fridge overnight, then reheat per above instructions. After heated through, top with the cheese and bake, uncovered, until melted.
- See more make ahead, freezing, and prep tips in my dump & bake casserole post.
More ways to use brown lentils
Did you try this recipe? You can leave a star rating in the recipe card or a review in the comments below. Or check out my cookbook and keep up to date with my YouTube, Instagram, TikTok, or newsletter!
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Lentil Mushroom Bake (Dump & Bake Casserole)
Inspired by shepherd's pie, this lentil casserole is a dump & bake recipe where the lentils cook completely in the oven.
Equipment
Ingredients
- 1 ½ cups dry brown lentils
- 3 ½ cups vegetable broth or water + 1 heaping tablespoon vegetable bouillon
- 2 medium russet potatoes roughly 1 pound potatoes
- 8 ounces sliced cremini (baby bella) mushrooms I buy pre-sliced for this recipe
- 12 ounces frozen mixed vegetables doesn't need to thaw first
- ⅓ cup roughly chopped walnuts optional
- 3 tablespoons tomato paste
- 2 tablespoons balsamic vinegar
- 1 tablespoon soy sauce or tamari to make gluten-free
- 1 teaspoon dry rosemary
- 1 teaspoon dry thyme
- 1 teaspoon garlic powder
- 1 teaspoon onion powder
- ¼ teaspoon kosher salt adjust to taste
- 2 cups (8 ounces) shredded Gruyere, Swiss, or mozzarella cheese see note #3
Instructions
- Preheat the oven to 400F. Rinse the lentils well in a fine-mesh sieve. Remove any debris.
- Bring 3 ½ cups water or vegetable broth to a boil in a kettle or on the stove top. Meanwhile, dice the potatoes into ½-inch cubes. The potatoes can be peeled first, if desired.
- Lightly oil a 9x13-inch baking dish. Add the lentils, cubed potatoes, sliced mushrooms, frozen mixed vegetables, walnuts, tomato paste, balsamic vinegar, soy sauce, rosemary, thyme, garlic powder, onion powder, and salt. Carefully stir in the boiling vegetable broth.
- Cover tightly with an oven-safe lid, foil, or an upside-down sheet pan. Bake at 400F for 45 minutes. Remove from the oven and check lentils and potatoes; if either aren't cooked through, return to the oven and cook, covered, for an additional 5-10 minutes.
- Stir the casserole. Top with shredded cheese. Return to the oven for 5 minutes and bake, uncovered, until the cheese is melted.
- Remove from the oven and let sit 5 minutes before serving. Enjoy!
Video
Notes
- Vegetable broth: I typically use Better than Bouillon vegetable base (1 teaspoon per cup water) and stir it into the casserole dish. If you're using vegetable broth instead of water + bouillon, simply heat it in a pot on the stovetop instead of in a kettle.
- Mushrooms: I buy pre-sliced mushrooms for this recipe to keep prep time short. Feel free to roughly or finely chop the mushrooms if you want them to "disappear" into the casserole more.
- Cheese: I use a blend of Gruyere and Swiss that's labeled as "Alpine Blend". Gruyere is a pricier cheese, so an equal amount of shredded mozzarella can be used instead, as needed.
- This recipe can be cut in half to make a smaller batch. Cut all ingredients, including broth, in half. Bake in an 8x8-inch baking dish instead of 9x13-inch.
Nutrition
Calories: 689kcalCarbohydrates: 70gProtein: 31gFat: 27gSaturated Fat: 13gPolyunsaturated Fat: 5gMonounsaturated Fat: 7gCholesterol: 75mgSodium: 945mgPotassium: 1489mgFiber: 23gSugar: 7gVitamin A: 4286IUVitamin C: 17mgCalcium: 564mgIron: 7mg
Did you make this?I love hearing how it went! Leave a review or tag me on Instagram @cozypeachkitchen so I can see your creations!
Mona says
I made this vegan by substituting a vegan cheese sauce for the shredded cheese topping. So yummy!
Clare says
This dish is spectacular, I did microwave the potatoes, not fully cooked, then sautéed, onion ,garlic and fresh spinach, it is a very colorful dish, now its in the oven, can't wait to try it, and sharing it with a vegan neighbor.
Cassidy Reeser, MS, RD says
Love those variations to make it even more nutritious and flavorful! I hope it was a hit with your neighbor 🙂
Karen McGregor-Lucchesi says
My husband is not a lentil fan, but he really enjoyed this dish! It’s so tasty and very simple to put together. Thanks for another incredible casserole!
Cassidy Reeser, MS, RD says
Woo! I always love to hear when someone finds a way to enjoy an ingredient they don't usually like. Thanks for leaving a review! 🙂
Jade says
Made this today and it's DELICIOUS! Adding this to my rotation for the fall - such an easy yet filling recipe!!
Cassidy Reeser, MS, RD says
Yay! Thanks so much for the review!
Renata says
This was such an easy delicious meal! We will be keeping this recipe on repeat.
Cassidy Reeser says
So happy to hear it! Thanks for the review!
Hilary says
This recipe looks fantastic!! Definitely going to make it this week. Can you please tell me what brand enameled cast iron casserole pan you are using? Thanks for all you do!!!
Cassidy Reeser says
It's Heart & Hand (Magnolia) brand from Target, but sadly it looks like they don't stock it anymore! I saw something similar at World Market but I don't think it has a lid. I hope that you enjoy the recipe and find something similar, I love this dish and wish they still made it!