Weeknight Lentil Soup with Ground Beef and Celery

Name: Weeknight Lentil Soup with Ground Beef and Celery
Prep time: 15 min
Cook time: 35 min
Total time: 50 min
Yield: 4 servings
Cuisine: American
Ingredients: 1 lb (450 g) lean ground beef; 1 (150 g) medium yellow onion, finely diced; 3 (200 g) celery stalks, cut into ½-inch pieces; 2 (200 g) medium carrots, peeled and cut into ½-inch rounds; 1 cup (200 g) brown lentils, rinsed; 6 cups (1420 ml) low-sodium vegetable broth; 2 tbsp (30 g) tomato paste; 2 (10 g) garlic cloves, minced; 1 (½ g) bay leaf; ½ tsp (½ g) dried thyme; ¾ tsp (4 g) kosher salt; ¼ tsp (½ g) freshly ground black pepper; 1 tbsp (15 ml) extra-virgin olive oil; ¼ tsp (½ g) red pepper flakes (optional)

From the MyKitchenBank Kitchen

A hearty, budget-friendly lentil soup built on browned ground beef, aromatic vegetables, and brown lentils that cook until tender in vegetable broth. Ready in under an hour, it's filling enough for a complete weeknight dinner and tastes even better the next day.

Prep: 15 min
Cook: 35 min
Total: 50 min
Makes: About 7 cups (serves 4 as a main course)

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Steps

Before you start

Rinse the lentils under cold water and pick through to remove any small stones or debris
Have all vegetables prepped before you start cooking—the soup comes together quickly once the beef hits the pan
If using homemade broth, let it come to room temperature

1
Brown the beef
- Set a large heavy-bottomed pot over medium-high heat.
- Add the ground beef, breaking it into bite-sized pieces with a wooden spoon as it hits the pot.
- Cook for 5 to 6 minutes, stirring occasionally, until the beef is no longer pink and has started to brown at the edges.
- Do not drain the fat—you'll use it to sauté the vegetables.
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Ready when: Beef is no longer pink and has started to brown; internal temperature reaches 160°F (71°C)
Tip: Breaking the beef into small pieces as it cooks ensures even browning and helps it cook faster.
2
Add aromatics and tomato paste
- Add the diced onion and celery pieces to the pot with the beef.
- Stir well and cook for 3 to 4 minutes, until the onion is softened and translucent.
- Push the beef and vegetables to the side, add the minced garlic and tomato paste to the empty space, and cook for 1 minute, stirring constantly.
- The tomato paste will darken slightly and smell sweet when it's ready.
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Ready when: Onion is translucent and tomato paste is darkened and fragrant
Tip: Cooking the tomato paste in fat for a minute deepens its flavor and prevents it from being raw-tasting.
3
Add broth, lentils, and aromatics
- Pour the vegetable broth into the pot and stir to combine, scraping up any browned bits from the bottom.
- Add the rinsed brown lentils, carrots, bay leaf, thyme, salt, and black pepper.
- Stir everything together until the lentils are distributed evenly.
- Bring the soup to a boil over medium-high heat, stirring occasionally.
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Ready when: Soup is at a rolling boil
Tip: Scraping up the browned bits from the pot adds depth and flavor to the broth.
4
Simmer until lentils are tender
- Once the soup reaches a boil, reduce the heat to medium-low and simmer uncovered for 25 to 30 minutes, stirring occasionally.
- The lentils should break down slightly but still hold their shape, and the soup should be thick and rich.
- If it seems too thick as it cooks, add a splash of broth or water.
- Taste the lentils to confirm they are tender.
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Ready when: Lentils are tender and easily break with a spoon; soup is thick and fragrant
Tip: Stir occasionally to prevent the lentils from sticking to the bottom of the pot and to ensure even cooking.
5
Adjust seasoning and finish
- Taste the soup and adjust the salt and pepper as needed.
- If you like a bit of heat, stir in the red pepper flakes.
- Remove the bay leaf.
- Drizzle the olive oil over the soup just before serving, or let each diner do so at the table.
- The soup is ready to eat now but benefits from sitting for 10 minutes off the heat, which allows the flavors to settle.
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Ready when: Soup is well-seasoned to your taste
Tip: A final drizzle of olive oil adds richness and a fresh, grassy note that brightens the soup.

Good to know

Tips

Brown the beef properly before adding vegetables—this creates a flavorful, savory foundation for the whole soup.
Don't skip rinsing the lentils. It removes dust and debris and helps them cook more evenly.
This soup thickens as it sits, which is why it reheats so well. If you prefer a brothier soup when serving, stir in extra broth or water after cooking.
Serve with crusty bread, a dollop of sour cream or Greek yogurt, and a sprinkle of fresh parsley for a restaurant-quality presentation at home.

Make ahead

Prepare the vegetables up to 1 day ahead and store them in an airtight container in the fridge. The soup itself can be made up to 3 days in advance; it thickens slightly as it cools but tastes wonderful reheated.

Storage & reheating

Room temperature: up to 2 hours. Refrigerator: up to 4 days in an airtight container. Freezer: up to 3 months in a freezer-safe container (leave ½ inch headspace). Reheat gently on the stovetop over medium heat, stirring occasionally, until warmed through. Add a splash of broth if the soup is too thick after thawing.

Substitutions

lean ground beef → ground turkey or ground lamb. Use the same weight. Ground turkey will be leaner; ground lamb adds a richer, earthier flavor.
brown lentils, rinsed → green (French) lentils or red lentils. Green lentils will hold their shape better and take the same time. Red lentils cook faster (15–18 minutes) and will break down more, creating a creamier soup.
low-sodium vegetable broth → beef broth or chicken broth. Beef broth adds deeper, meatier flavor; chicken broth is lighter. Use the same quantity.
dried thyme → oregano or Italian seasoning. Use the same amount for oregano; reduce Italian seasoning to ¼ teaspoon if it contains more potent herbs.