Lentils Gratin with Vegetables
This lentil and veggie gratin is a hearty vegetarian bake that layers protein-rich red lentils, sauteed root vegetables and mushrooms into a savory casserole, then crowns it with a crisp breadcrumb-and-Parmesan crust. It is budget-friendly, deeply satisfying, and the kind of one-dish meal that wins over even the most committed meat eaters. If you want a comforting main that comes together from pantry staples, this is the one to make.
I stumbled upon this gratin technique while watching a cooking TV show, and I have been hooked ever since. The secret lies in achieving that perfect crispy crust, transforming an ordinary casserole into a culinary masterpiece. Trust me, this recipe is an absolute game-changer.
What goes into this lentil gratin
The base is one cup of red lentils, boiled for about 20 minutes until tender. Red lentils are the right pick here because they cook quickly and turn soft and creamy, which helps bind the bake together. The vegetables — carrot, parsnip, celeriac, onion and mushrooms — bring sweetness, earthiness and that satisfying “meaty” bite from the mushrooms.
Grated feta is folded through the mixture for a salty tang, while beaten eggs act as the binder that sets everything as it bakes. The topping is a simple mix of breadcrumbs and grated Parmesan, which is what gives you that golden, crackly crust. A bunch of chopped parsley keeps it fresh, and salt and pepper season it to taste. If you are gluten-free, swap in GF breadcrumbs and the recipe works just the same.
Why the breadcrumb crust works
Mixing the breadcrumbs with grated Parmesan before spreading them over the top is the key move. As the gratin bakes, the cheese melts into the breadcrumbs and the fat helps them brown and crisp instead of drying out, giving you a crust with real crunch and flavor rather than a dusty layer. The beaten eggs underneath do the structural work: they coagulate in the oven and lock the lentils and vegetables into sliceable portions, so the casserole holds its shape when you serve it.
Tips for getting it right
- Saute the carrot, parsnip, celeriac, onion and mushrooms for the full 10 minutes before mixing. Softening them first means they finish cooking in the oven and release some moisture, so the bake is not watery.
- Drain the boiled lentils well. Excess cooking water can make the mixture loose and slow the eggs from setting.
- Oil the casserole dish before adding the mixture so the bottom does not stick and the edges crisp up.
- Spread the breadcrumb-Parmesan topping in an even layer so the whole surface browns at the same rate.
- Bake at 180-200C (350-400F) for about 40 minutes. The gratin is done when the top is deep golden and the center feels set rather than jiggly.
What to serve with it
This gratin is filling enough to stand as a main, so I like to keep the sides light and fresh. A simple green salad or a plate of spring roasted veggies rounds it out nicely. If you are cooking for a crowd or building a vegetarian spread, it sits well next to a veggie and mushroom bake or a tray of baked scallions with za’atar.
Make-ahead and storage
This bake keeps beautifully, which makes it great for meal prep. Once cooled, store leftovers in an airtight container in the fridge for up to 4 days. Reheat individual portions in the oven or a toaster oven to bring the crust back to life — the microwave works in a pinch but softens the topping. You can also assemble the whole casserole ahead, refrigerate it unbaked, and slide it into the oven when you need it (allow a few extra minutes if it goes in cold). If you fall in love with red lentils the way I have, browse more lentil recipes — the lentil patties with olives and herbs and the cozy moudardara, lentils with rice, are both worth a spot in your rotation.
If you make this lentil and veggie gratin, I would love to know how that crispy Parmesan crust turned out for you. Leave a rating and drop a comment below with any tweaks you tried, whether it was a different vegetable in the mix or your favorite GF breadcrumbs.
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Lentils Gratin
Ingredients
Instructions
- Saute the carrot, parsnip celery root, onion and mushrooms in a little bit of olive oil for about 10 minutes.
- Mix the following ingredients in a large bowl: sauteed veggies and mushrooms, grated feta cheese, beaten eggs, boiled red lentils, parsley, salt and pepper.
- Put the composition in a previously oil-coated casserole.
- In a separate bowl mix the breadcrumbs with grated Parmesan and spread evenly over the veggies in the casserole.
- Bake for 40 minutes at 180-200 degrees Celsius.
Frequently Asked Questions
No, this is a vegetarian recipe, not vegan. It contains feta cheese, beaten eggs and grated Parmesan, all of which are animal products. To make it plant-based you would need to swap the cheeses for vegan alternatives and replace the eggs with a binder, which would change the texture.
Red lentils are ideal here. They cook in about 20 minutes and break down into a soft, creamy texture that helps bind the bake together. Brown or green lentils hold their shape more and stay firmer, so they would give a chunkier, less cohesive result.
Yes. The only ingredient with gluten is the breadcrumbs, and you can use gluten-free breadcrumbs in their place. The rest of the recipe — lentils, vegetables, cheese and eggs — is naturally gluten-free.
These root vegetables add earthiness and sweetness, but you can adjust to what you have. More carrot, a bit of potato, or other firm root vegetables will work. Just keep the total volume similar and saute everything together for about 10 minutes so it softens before baking.
Store cooled leftovers in an airtight container in the fridge for up to 4 days. Reheat portions in the oven or a toaster oven to crisp the breadcrumb topping back up. The microwave works if you are short on time, but it softens the crust.
Two things usually cause this: vegetables that released too much moisture, or lentils that were not drained. Saute the vegetables for the full 10 minutes first and drain the boiled lentils well. The beaten eggs need to coagulate to set the bake, so excess liquid slows that and leaves it loose.
Very good! Made this last week.
I wasn’t a fan of lentils, but I must say that this recipe is ahhh-mazing indeed! I would love to make it again.
I love your blog, btw!!
Thank you! 🙂 Glad you liked the recipe!
Buna!Arata delicios!Eu cu linte nu am incercat varianta aceasta, chiar nu stiu de ce?!Dar acum ca am vazut ce bine arata , o voi prepara neaparat!Ma poticnesc mereu cand vreau sa prepar naut ,mei,linte …nu imi vin idei prea repede!Caut retete peste tot , mai inventez eu combinatii , dar inca nu sunt multumita…!Nautul tind de fiecare data sa il transform in hummus , ca i-am innebunit pe ai mei :)!Lintea la fel , imi place sub forma de pateu!Diversitatea retetelor tale e mare , asa ca ma bucur cand ma inspira ceva bun!Te salut! Mihaela B.
Buna Mihaela!
Ma bucur ca iti place!
Cu nautul si meiul ma cam chinui si eu…tot asa numai hummus fac din naut..aa si falafel :)) In schimb linte mananc fff des si experimentez mereu cu ea. De obicei fac chiftelute, supe, mancaruri la tava cum e aceasta. Te sfatuiesc sa folosesti linte rosie. E mult mai buna la gust, arata mai bine si se fierbe ff repede (in max. 15 minute). Am facut zilele trecute o mancare de linte, ff buna a iesit! Cu siguranta o sa mai refac reteta si o sa o pun pe blog.
Te pup!
What is red lintels
Lentils are some kind of beans, very rich in protein and other nutrients. Please check wiki for more info.
i tried this recipe with high hopes mine turned out very dry and im guessing the recipe in the pick is a bit different the the recipe given as that is clearly not just parm on the top i will try it again with some tweaks to get it right
I’m sorry to hear that. Did you follow the exact quantities in the recipe? Mine was actually gooey and moist in the middle, because of the cheese, and crunchy on the outside. On top it’s just parmesan mixed with breadcrumbs, that’s how you make the gratin crunchy texture.
Hi, I was wondering whether there was an alternative to the cheese? My boyfriend is very dairy intolerant 🙁
Hi Juliet! You can use crumbled tofu inside the composition. On the outside, for the gratin effect, you can use 2-3 Tbsps of nutritional yeast mixed with 2 egg yolks and breadcrumbs. This way you’ll replace parmesan and still achieve that crunchy texture and nice color.
I forgot to mention how to do it. The last step in the recipe is to achieve the gratin effect. So instead of mixing Parmesan with breadcrumbs, you’ll mix nutritional yeast with breadcrumbs, spread it evenly, then pour whisked egg yolks over, and using a brush, spread them all over the casserole. Hope this helps 🙂
When I signed up for this I mistakenly though this was vegan. The dairy & egg industry is just as vile, deadly & bloody as the meat industry. I have to find out how to unsubscribe 🙁
Sheryl, feel free to unsubscribe. I am vegetarian and my recipes are vegetarian also. If you’ve read any of my posts then you would probably know that I DO NOT encourage the consumption of dairy and egg products from supermarkets/industrialized sources, ONLY from FARMERS who treat their animals accordingly. I, for example, only eat eggs and dairy products from a safe source (a friend of mine has a small farm). Those are happy animals, non-GMO fed and hormone-free.
Nice, polite response to an inappropriately rude comment. I love your blog. Can’t wait to start trying some recipes!
Thanks Kij! Hope you’ll like them! 🙂
Thank you for a simple but great recipe! The whole family enjoyed it. I’m looking forward to trying more recipe from your site.
That’s great to hear Monica! I’m really glad you and your family liked it.
great recipe! I like the simplicity and the ability to mix your own blend of vegetables!
Thank you! Glad you like it!
Thanks! Love your website!
Tocmai am terminat aceasta reteta , si desi nu sunt un fan linte rosie pot spune cu inima deschis ca m-am indragostit ! Pentru ca nu imi place lintea am avut asteptari foarte mici, dar e nemaipomenita 😀 I really like your website ! Keep up the good work 🙂
Super! Ma bucur tare mult ca ti-a placut 😀 Sa incerci si drobul cu linte, e minunat!