This Lentil Casserole with Mushrooms combines lots of wholesome vegetables with hearty lentils and flavorful mushrooms, a creamy sauce, and a cheesy topping.
We also love this chicken and lentil casserole, green lentil curry and mushroom bean soup.
Table of Contents
When I first made this lentil casserole recipe I liked lentils but had no special love for them. In fact, I pretty much dedicated them towards making soups like this spinach lentil soup and lentil chicken soup.
Since then I’ve come to appreciate them a little bit more with this lentil casserole.
Originally I only cooked lentils because of their health benefits, not because I wanted to. Now I’m starting to appreciate how versatile they are, especially combined with lots of flavorful veggies and a cheesy topping! A little cheese makes everything better!
And this casserole recipe has ticked off all of the above points.
Ingredients You Will Need
To make this lentil casserole you will need just a few simple ingredients.
- Green lentils
- Cream of mushroom soup
- Cheese
- Vegetables like onion, celery, carrots and brown mushrooms
- Simple seasonings
- Oil for frying
How to Make Lentil Casserole with Mushrooms
Preheat large non-stick ceramic skillet on medium heat and swirl 2 tbsp oil to coat. Add onion and sauté for 3 minutes, stirring occasionally.
Add celery and carrots, sauté for 5 minutes, stirring occasionally. Transfer to previously prepared baking dish (everything gets mixed here). 
Return skillet to high heat and add mushrooms. Sauté for 5-7 minutes or until a bit browned, draining liquid into the baking dish as necessary (flavourful broth for baking) and stirring occasionally. Transfer mushrooms to the baking dish.
Return skillet to low heat and add remaining 1 tbsp of oil, along with thyme and garlic powder. Cook for 30 seconds, stirring constantly. Add lentils and cook for 2 minutes. Add water, bring to boil and transfer to the baking dish scraping the bits off the bottom of the skillet.
Uncover and bake for another 15 minutes. Then sprinkle with cheese and bake for 5 more minutes or until cheese is melted. Remove from the oven, cover and let stand for about 20 minutes (very important – casserole is just tastier this way). Serve hot on its own or over spinach, greens, brown rice or whole grain pasta.
Add mushroom soup, salt and ground black. Stir well, cover and bake for 30 minutes. 
More Lentil Recipes to Try
Lentil Casserole with Mushrooms
Equipment
Ingredients
- 1 large onion finely chopped
- 3 large celery stalks finely chopped
- 2 large carrots coarsely grated
- 3 tablespoons oil for frying
- 1 pound brown mushrooms sliced
- 1 teaspoon garlic powder
- 1/2 teaspoon dried thyme
- 1 1/2 cups green lentils uncooked & rinsed
- 11 ounces can organic cream of mushroom soup I use Pacific Foods or Simple Truth
- 1/4 teaspoon salt
- 1/2 teaspoon ground black pepper
- 2 cups water or low sodium vegetable broth
- 1 cup mozzarella cheese shredded
- Cooking spray
Instructions
- Preheat oven to 375 degrees F and spray large 9×13 baking dish with cooking spray. Set aside.
- Preheat large skillet on medium heat and swirl 2 tablespoons of oil to coat. Add onion and sauté for 3 minutes, stirring occasionally. Add celery and carrots, sauté for more 5 minutes, stirring occasionally. Transfer to previously prepared baking dish (everything gets mixed here).
- Return skillet to high heat and add mushrooms. Sauté for 5-7 minutes or until a bit browned, draining liquid into the baking dish as necessary (flavourful broth for baking) and stirring occasionally. Transfer mushrooms to the baking dish.
- Return skillet to low heat and add remaining 1 tablespoon of oil, along with thyme and garlic powder. Cook for 30 seconds, stirring constantly. Add lentils and cook for 2 minutes. Add water or broth, bring to a boil and transfer to the baking dish, scraping the bits off the bottom of the skillet.
- Add mushroom soup, salt and ground black. Stir well, cover and bake for 30 minutes. Uncover and bake for another 15 minutes. Then sprinkle with cheese and bake for 5 more minutes or until cheese is melted.
- Remove casserole from the oven, cover and let stand for about 20 minutes (very important – casserole is just tastier this way). Serve hot on its own or over spinach, greens, brown rice or whole grain pasta.
Notes
- Store: Refrigerate in an airtight container for up to 3 days.
- Freeze: In an airtight container for up to 3 months.
Made this for Thanksgiving; added a splash of red wine. It’s very good and turns out it’s even better the next day and without cheese. Will make this again.
So happy to hear!
I have made this several times now. Unusually for me, I just about follow the recipe as it is! I use lots of dried tarragon, ground black pepper, red lentils and a sprinkling of chilli plus extra onions cooked well. It’s a delicious recipe which is enjoyed by both vegetarians and meat eaters. It’s even better reheated the following day ( in the unlikely event that there are any leftovers!
So glad you enjoy the recipe!
Can I substitute red lentils
I prefer green lentils as red lentils can turn out a bit more mushy. But you can give it a try!
We liked that it was cooked abotu 10 minutes shy of the recipe bc we like some texture to the lentils. Add beef bouillon one cube to enhance flavor.
Awesome! Thanks for sharing Kimberely!
What can I use instead of cream of mushroom soup. Staying home.
You can make a homemade cream of mushroom soup substitute. Check out this website for ideas! https://www.recipesthatcrock.com/homemade-substitute-cream-mushroom/
Can you use canned lentils rather than dry?
Yes. Follow the recipe and instead of 2 cups water use only 1/4 cup. Enjoy!
I thought this was a very good casserole however I don’t like crunchy lentils so I baked it 1-1/2 hours and stirred it while it was baking to make sure the it cooked evenly. Will definitely make during Lent!
This lentil casserole was delicious. I will definitely make it again.
So happy to hear, Cathi! Lentils are so cheap and good for you!
Super delicious for a lentil casserole lol.
Looks yummy! So you add the 2 cups of boiling water to the lentils, then bring that mixture to a boil? Are you just looking for a rolling boil before you transfer to the baking dish, so the lentils are basically going to cook in the oven? Thank you!
Yes. Lentils cook in the oven.