A quick and easy, thick and hearty, Red Lentil Soup with Lemon. It’s fragrant, super yum, healthy, nourishing, simple and versatile!
Things you need to know about this Red Lentil Soup with Lemon … It is PACKED with flavor (yes throw out ALL of your lentil preconceptions), it’s thick and hearty in an almost cross between soup and stew kinda way, and it’s lemony and garlicky and fragrant, and packed with vegetables.
It’s also super healthy and really flexible. Not got one of the veggies? Leave it out or throw in whatever you do have. You can even omit the lemon and it still tastes amazing.
I’ll give some ideas for great subs/additions in my “ways you can adapt this recipe” section below.
How to make Red Lentil Soup with Lemon
FOR THE FULL LIST OF INGREDIENTS & INSTRUCTIONS PLEASE SEE THE RECIPE CARD AT THE END OF THIS POST
It starts with the usual soup gang … onions, garlic, celery, carrots and stock but then along to the party come:
- red lentils
- dried herbs
- kale or other greens of choice
- excessive amounts of zippy, fresh lemon juice
It’s savory, but fresh and bright. It’s healthy, pantry friendly, but also warm and cozy comfort food.
Here’s how it’s done:
Step 1 – Sauté the onions, carrots and celery (so important for amping up those flavors so don’t rush them!)
Step 2 – Add the lentils, potatoes, garlic, herbs and seasonings and cook a bit more.
Step 3- Add the stock and give it a good stir.
Step 4 – Simmer until the lentils and veggies are tender.
Step 5 – Add the greens and let them simmer for a few minutes.
Step 6 – Turn off the heat, add the lemon juice, stir and serve.
Do red lentils need to be soaked?
Red lentils cook and break down so quickly that there is no need to soak them before using.
Because of this they aren’t a great choice for recipes where you need the lentils to retain their shape, but they are perfect for making soups, dhals and stews.
Before using them in a recipe rinse them well in cold water ( a sieve is great for this) because they can sometimes be a bit dusty. Also give them a quick pick through to check for small stones, then proceed with the recipe as instructed.
- Red lentils are best in this recipe because they break down and thicken the soup really well giving it great texture. If you only have green or brown lentils see the recipe notes for instructions on how to adapt the recipe.
- Don’t use French (Puy) lentils. They remain too firm to work well in this recipe.
- Be sure to take your time sautéing the vegetables at the start. The caramelization that occurs is so important for flavor.
- Season generously.
- Although you can customize the thickness of the soup by increasing the stock/water added if you want to, I recommend keeping it pretty thick. It’s best that way.
- Old lentils dry out and can take significantly longer to cook. Check the use by date on bags from the grocery store and if buying from bulk bins, make sure it’s one that gets refreshed often, not one where the lentils have been languishing for the past 3 years.
- Use dried lentils not canned if at all possible, although if you’re stuck see my recipe notes for how to adapt the recipe for canned lentils.
Ways you can adapt this recipe
This is a really flexible recipe and you can switch up most of the ingredients to suit what you have on hand. Here are ideas for adapting it:
- Use sweet potatoes instead of regular potatoes
- Use spinach (fresh or frozen), collard greens or Swiss Chard instead of kale
- Omit the greens completely
- Omit the lemon
- Add leftover cooked grains (like brown rice, sorghum, farro or quinoa) at the end of cooking to it to make it even more thick and hearty
- Add a teaspoon of ground turmeric or curry powder
- Red lentils are best in this recipe. See my recipes notes for tips on how to adapt the recipe if you use a different kind.
What do you eat with Red Lentil Soup?
I like to serve this Red Lentil Soup with some lemon wedges for everyone to squeeze over their own individual bowls, and some vegan parmesan cheese. I love Violife Just Like Parmesan Wedge.
My vegan feta cheese (the unbaked version) is also a great addition. Its creamy, melty saltiness works really well with the lemon and lentils.
Plain coconut yogurt, fresh parsley and croutons also work well as toppers!
With all of those lentils and the potatoes this is a seriously hearty soup, but if you’re like me and always need something on the side regardless, then here are some ideas:
Storage, freezing and reheating tips
Allow the soup to cool completely then store in the fridge for up to 5 days. Reheat in a pan on the stove top or in a microwave. It does thicken a lot as it cools, so add additional water or stock as needed.
It can also be frozen for up to 3 months. Allow to thaw completely in the fridge then reheat as above.
How to store red lentils
Red Lentils should be stored in an airtight container in a cool, dry place.
If stored correctly they can last well for up to a year. If stored incorrectly or after they go past about a year old, they can become drier and tough and end up taking ages to cook or never actually soften well at all.
Be sure to check the use by dates on beans and pulses when you buy them, and if you are buying them from bulk bins, make sure it’s from a store with a high turnover so you know you won’t be getting old ones that won’t cook well.
Meal prep tips
To reduce prep time, feel free to chop the veggies a couple of days before hand. Put them in an airtight container in the fridge. the potatoes will need to be covered with water to stop them going brown but the others are all fine as they are.
Once the soup is cooked and cooled, it will keep for up to 5 days in the fridge so it’s great for meal prep. Or freeze it in individual sized containers. It will keep for 3 months in the freezer.
How to make in an Instant Pot
Sauté the onions, celery and carrots in your Instant Pot as per the recipe. Then press off and add the lentils, potatoes, herbs and seasoning. Allow them to cook in the residual heat for a few minutes. Add the stock and scrape the bottom of the Instant Pot really well with a metal spoon.
Put the lid on, seal and cook on Manual High Pressure for 8 minutes. Carefully let out the steam, take the lid off and add the chopped greens. Press sauté and allow it to simmer until the greens are cooked. Turn off, squeeze in the lemon and serve.
How to make in a slow cooker
I recommend sautéing as per the recipe for the very best flavor. Then put everything in the slow cooker (except the lemon and greens) and cook on high for 3 hours or low for 5 to 6 hours. Once everything is tender, add the greens and allow them to wilt down. Turn off the heat. Add the lemon juice and serve.
Hungry for more?
Want more super yum lentil recipes?
- Creamy Red Lentil Dahl – Super delicious, easy and packed with flavor. Highly recommend you try it!
- Lentil Shepherd’ Pie – A real favorite in our family. Proper comfort food!
- Vegan Meatloaf – A reader favorite!
- Keema Lentils – If you like curry you’ll love this one!
- Indian Lentil Soup – Perfectly spiced and delicious.
- Cozy Slow Cooker Spicy Lentil Soup – A great hands off soup that makes LOADS!
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Red Lentil Soup with Lemon
- 1 tablespoon olive oil , (omit to make oil-free and use a few drops of water to sauté instead)
- 1 large onion , diced
- 3 sticks celery , diced
- 2 large carrots , diced
- 5 cloves garlic , chopped finely
- 3 – 4 potatoes , diced
- 1½ cups / 300 g split red lentils , sometimes labelled Masoor Dal
- 1 tablespoon dried mixed herbs , see notes
- 2 teaspoons salt
- ½ teaspoon freshly ground black pepper
- 6 – 7 cups / 1440 mls – 1680 mls stock
- 1 tablespoon sugar , see notes
- 3 fresh lemons
- 4 – 5 big handfuls chopped kale or other greens of choice , see notes
- Warm a large soup pan or Dutch Oven over a medium heat and add the olive oil.
- Sauté the onion, celery and carrots together until turning golden. Don't rush them. It will take about 10 minutes.
- Add the garlic, potatoes, lentils, herbs, salt and pepper and continue to cook for a few minutes.
- Add 6 cups of the stock and the sugar and stir well. Bring to a simmer and cook uncovered until the potatoes are fork tender and the lentils have more or less broken down. It should take about 20 minutes. Check the thickness. If you prefer it thinner add the rest of the stock. (Remember that lemon juice goes in at the end and will thin it a little more).
- Add the greens, stir and allow to cook in the simmering soup for 5 minutes, unless you are using spinach, in which case it will be cooked more or less immediately once it's been stirred in.
- Turn off the heat. squeeze in the juice of the 3 lemons, stir well. Taste to check seasoning and add more as necessary. Check the thickness again. Add some hot water from the kettle if you want to thin it down, then serve immediately.