Red Lentil Soup

This red lentil soup is a thick, golden soup of red lentils simmered with onion, carrot, celery, garlic, tomatoes and warm spices, finished with a squeeze of lemon. Red lentils cook down in about 20 minutes with no soaking, so the whole soup takes about 40 minutes. It serves 4, and each bowl has about 13 g of protein and 8 g of fiber. It’s vegan, filling and keeps well for lunches.

• Serves: 4
• Prep time: 10 minutes
• Cook time: 30 minutes
• Total time: about 40 minutes

Ingredients

• 1 tablespoon olive oil
• 1 medium onion (about 150 g), chopped
• 2 carrots (about 120 g), diced
• 1 celery stick, diced
• 2 garlic cloves, finely chopped
• 1 teaspoon ground cumin
• ½ teaspoon ground turmeric
• ½ teaspoon sweet or smoked paprika
• 200 g (1 cup) red lentils, rinsed
• 200 g (about half a 400 g can) chopped tomatoes
• 1 litre (4 cups) low-salt vegetable stock or water
• 1 tablespoon lemon juice, plus wedges to serve
• ¼ to ½ teaspoon salt and black pepper
• Fresh parsley or cilantro, chopped, to serve

Method

1. Heat the oil in a large saucepan over medium heat. Add the onion, carrot and celery and cook for 6 to 8 minutes, stirring now and then, until softened.
2. Stir in the garlic, cumin, turmeric and paprika and cook for 1 minute, until fragrant.
3. Add the lentils, tomatoes and stock. Bring to a boil, then lower the heat, partly cover and simmer for 20 to 25 minutes, stirring occasionally, until the lentils have broken down and the carrots are soft.
4. For a smooth soup, blend it with a stick blender, or blend half and stir it back in for a chunkier texture.
5. Add water if it’s too thick. Red lentil soup thickens as it stands.
6. Stir in the lemon juice, then season with salt and pepper to taste.
7. Serve topped with herbs, a little olive oil and lemon wedges.

Tips

• Rinse the lentils in a sieve until the water runs clearer. It removes dust and some of the foam that forms when they cook.
• Skim the foam that rises in the first few minutes of simmering, if you like a cleaner soup.
• Don’t skip the lemon. A squeeze of acid at the end brightens the earthy lentils.
• Season at the end. Stock can be salty, so taste first.
• Bloom the spices in the oil for a minute before adding liquid, for more flavor.

Swaps and variations

• Coconut: replace 250 ml of the stock with light coconut milk for a creamier soup.
• Spicier: add a chopped red chili or ½ teaspoon of chili flakes with the garlic.
• Greens: stir in two handfuls of spinach or chopped kale for the last 3 minutes.
• Lemony Middle Eastern style: skip the tomatoes and add more lemon and cumin.
• Heartier: serve with brown rice, or add a can of drained chickpeas.

Nutrition per serving (estimate)

One serving is a quarter of the soup, about 375 ml (1½ cups). These figures were calculated from USDA FoodData Central values for red lentils, onion, carrots, celery, garlic, olive oil, spices, canned tomatoes, lemon juice and salt. Stock isn’t included, so sodium will be higher if you use a regular stock.

Lentils are one of the cheapest sources of plant protein and fiber. A bowl of this soup gives you more than a quarter of the 30 g of fiber the NHS recommends for adults each day. Lentils also provide iron, so serving the soup with a vitamin C-rich food, such as a squeeze of lemon or a tomato salad, helps your body absorb it. Our guide to iron-rich foods explains how.

Our high-fiber foods list shows how lentils compare with other beans and grains.

Contains: celery. Check your stock for other allergens. The soup is vegan and naturally gluten-free if your stock is.

Storage and reheating

Cool the soup quickly, then cover and refrigerate it within 2 hours. Eat it within 3 to 4 days, as the USDA advises for leftovers. Reheat until steaming hot all the way through, adding a splash of water because it thickens in the fridge.

Lentil soup freezes very well. Freeze it in portions for up to 3 months and thaw it overnight in the fridge before reheating.

What to serve with it

• Warm whole grain bread or pita.
• A crisp salad with cucumber and tomato.
• A spoonful of plain yogurt on top, if you’re not keeping it vegan.
• For a lighter lunch, a small bowl with our hummus and vegetable sticks.

Common questions

Do I need to soak red lentils?

No. Red lentils are split and cook quickly without soaking. Green and brown lentils also don’t need soaking, but take longer to cook.

Why didn’t my lentils soften?

Old lentils can take longer to cook, and adding acidic ingredients too early can slow them down. Simmer for longer, adding water as needed, and add the lemon at the end.

Can I make it in a slow cooker?

Yes. Soften the onion and spices in a pan first, then cook everything except the lemon on low for 6 hours or high for 3 hours.

This article is general information, not medical advice. Nutrition figures are estimates from USDA FoodData Central and will change with the brands and amounts you use. If you follow a diet for a medical reason, check the recipe with your doctor or dietitian.