This healthy vegan soup is made with protein-rich red lentils and fresh vegetables, like carrots, potatoes, and leafy greens. Fire-roasted tomatoes add depth of flavor. Serve this easy red lentil soup on its own or with a side of bread. It's perfect for soup season! (Vegan & Gluten Free)
1bunchSwiss chard, chopped(about 10 oz/283g, see note 3)
1tablespoonred wine vinegar(see note 4)
Instructions
Saute vegetables: Warm 2 tablespoons of the olive oil in a large Dutch oven or pot over medium heat. Add onion and cook, stirring occasionally, until golden brown around the edges, 8 to 10 minutes. Add carrots and celery, cook, stirring occasionally, for 2 minutes to soften.
Add spices: Use a stirring spoon to push the vegetables to the edges of the pot. Pour the remaining 2 tablespoons olive oil into the middle of the pot, then sprinkle cumin into oil. Once it starts to sizzle, add garlic, thyme, and salt. Cook, stirring frequently, until the garlic is fragrant, 1 to 2 minutes.
Simmer: Pour in the vegetable broth and use a stirring spoon to loosen any brown bits from the bottom of the pot. Add the potatoes and red lentils. Stir to mix. Cover with a lid, increase heat to medium high, and bring to a boil. Once boiling, reduce the heat to maintain a simmer with the lid slightly ajar. Cook, stirring occasionally, until the lentils are soft and potatoes are tender, about 15 minutes.
Finish and season: Stir in the tomatoes, then bring the mixture back to a boil (keep the lid slightly ajar and increase heat slightly). Once boiling, stir in the Swiss chard to wilt the leaves. Remove from heat. Add red wine vinegar. Taste and season with more salt if needed (see note 5).
Video
Notes
Potatoes: If using yellow potatoes, you don't need to peel them. You can substitute with other potatoes if you prefer (such as red potatoes or Russet).
Fire-roasted tomatoes: Or, 2 smaller 14 fl oz/398 ml cans. You can use crushed fire-roasted tomatoes instead of diced. Fire-roasted tomatoes add an extra depth of flavor, but if you can't get them, you can substitute whole peeled San Marzano tomatoes from a can (crush them with your hands as you add the tomatoes and their juices to the pot).
Swiss chard: We use the leaves and stalks (slicing the stalks thinly so that they soften at a similar time as the leaves). But if you're not a fan of the stalks, leave them out. Instead of Swiss chard, you could substitute thinly sliced kale or spinach.
Red wine vinegar: A small splash of vinegar (acid) really helps brighten up flavors in dishes. We prefer red wine vinegar in this soup, but in a pinch you could use a squeeze of fresh lemon or white wine vinegar instead.
Thinning soup: If the soup is too thick for your liking, you can thin it with extra vegetable broth or water. When reheating soup the next day, you'll likely want to thin it slightly with a splash more liquid.
Storage and reheating: Refrigerate extra soup in an airtight container. Reheat the soup in a pot on the stove, over medium heat, covered with a lid. You may want to add a splash of water or vegetable stock to thin. This soup can also be frozen. Defrost frozen soup (either in the fridge overnight or in a cold water bath), then reheat on the stove as directed. When freezing soups, we prefer to hold off on adding tender greens (in this case, the Swiss chard)—then add the greens when reheating on the stove...but this is up to you!