Quick Recipe Version (TL;DR)
Quick Ingredients
- 1 lb (450 g) Italian sausage, casings removed
- 1 tbsp olive oil
- 1 medium yellow onion, diced
- 2 medium carrots, diced
- 2 celery stalks, diced
- 3 garlic cloves, minced
- 1.5 cups (300 g) green lentils, rinsed
- 2 tbsp tomato paste
- 1 (14.5 oz / 410 g) can diced tomatoes, with juices
- 6 cups (1.4 L) low-sodium chicken broth + 1 cup water
- 2 tsp fresh rosemary, finely chopped
- 1 tsp dried oregano, 1 bay leaf, pinch red pepper flakes
- 1 tbsp balsamic or red wine vinegar
- Salt and freshly ground black pepper
- Grated Parmesan and chopped parsley, for serving (optional)
Do This
- 1. Prep all vegetables, rinse lentils, and remove casings from the sausage.
- 2. Brown sausage in olive oil over medium-high heat until deeply golden; spoon off excess fat if needed.
- 3. Add onion, carrots, and celery; cook until softened, then stir in garlic and tomato paste until fragrant.
- 4. Add lentils, diced tomatoes, broth, water, rosemary, oregano, bay leaf, and red pepper flakes; bring to a boil.
- 5. Reduce to a gentle simmer, cover partially, and cook 30–35 minutes until lentils are tender, stirring occasionally.
- 6. Stir in vinegar, season with salt and pepper, adjust thickness with more water if needed, and serve with Parmesan and parsley.
Why You’ll Love This Recipe
- Hearty and satisfying: lentils and Italian sausage make this a true meal-in-a-bowl.
- Weeknight-friendly: mostly hands-off simmering and ready in about an hour.
- Budget-conscious: uses simple pantry ingredients that stretch to feed a crowd.
- Flexible: easy to make spicier, lighter, or bulked up with extra veggies or greens.
Grocery List
- Produce: 1 yellow onion, 2 carrots, 2 celery stalks, 3 garlic cloves, fresh rosemary, fresh parsley (optional)
- Dairy: Parmesan cheese (for serving, optional)
- Pantry: Olive oil, green lentils, tomato paste, 1 can diced tomatoes, chicken broth, bay leaf, dried oregano, red pepper flakes, balsamic or red wine vinegar, salt, black pepper
- Meat: 1 lb (450 g) Italian sausage (mild or hot)
Full Ingredients
For the Soup
- 1 lb (450 g) Italian sausage, casings removed (use mild, hot, or a mix)
- 1 tbsp olive oil
- 1 medium yellow onion, diced (about 1.5 cups)
- 2 medium carrots, peeled and diced (about 1 cup)
- 2 celery stalks, diced (about 1 cup)
- 3 garlic cloves, minced
- 1.5 cups (about 300 g) green lentils, picked over and rinsed
- 2 tbsp tomato paste
- 1 (14.5 oz / 410 g) can diced tomatoes, with juices
- 6 cups (1.4 L) low-sodium chicken broth
- 1 cup (240 ml) water, plus more as needed to adjust thickness
Herbs & Seasoning
- 2 tsp fresh rosemary, finely chopped (plus extra for garnish)
- 1 tsp dried oregano
- 1 bay leaf
- 1/4–1/2 tsp crushed red pepper flakes (optional, to taste)
- 1 tsp kosher salt to start, plus more to taste
- 1/2 tsp freshly ground black pepper, plus more to taste
- 1 tbsp balsamic or red wine vinegar (for finishing)
For Serving (Optional but Recommended)
- Fresh flat-leaf parsley, chopped
- Fresh rosemary leaves, very finely chopped
- Freshly grated Parmesan cheese
- Crusty bread, for dunking
Step-by-Step Instructions
Step 1: Prep your ingredients
Gather all ingredients before you start cooking. Dice the onion, carrots, and celery into small, even pieces so they cook at the same rate. Mince the garlic. Rinse the green lentils under cold water and pick out any small stones or debris. Finely chop the fresh rosemary and parsley (if using for garnish).
Remove the casings from the Italian sausage if they are still on: use a sharp knife to slit the casing lengthwise, then peel it off and discard. Break the sausage into bite-sized chunks with your hands or a spoon. Having everything prepped will make the cooking process smooth and relaxed.
Step 2: Brown the Italian sausage
In a large heavy-bottomed pot or Dutch oven, heat the olive oil over medium-high heat. Add the crumbled Italian sausage in an even layer. Let it cook without stirring for 2–3 minutes so it can develop a good brown crust, then stir and continue cooking for another 4–6 minutes until the sausage is well browned and cooked through.
If a lot of fat renders out, spoon off and discard some, leaving about 1–2 tablespoons in the pot. The browned bits on the bottom of the pot are packed with flavor; you will loosen them in the next step to enrich the broth.
Step 3: Sauté the aromatics
Reduce the heat to medium. Add the diced onion, carrots, and celery to the pot with the sausage. Cook, stirring occasionally, for 6–8 minutes, until the vegetables have softened and the onion is translucent. Use a wooden spoon to scrape up the browned bits from the bottom of the pot as the vegetables release moisture.
Add the minced garlic and cook for 30–60 seconds, just until fragrant. Stir in the tomato paste and cook for 1–2 minutes, stirring constantly. The tomato paste should darken slightly in color and smell sweet and rich; this brief toasting step deepens the flavor of the soup.
Step 4: Add lentils, tomatoes, broth, and herbs
Add the rinsed green lentils to the pot and stir to coat them in the aromatic mixture. Pour in the diced tomatoes with their juices, the chicken broth, and 1 cup of water. Stir to combine well.
Add the chopped fresh rosemary, dried oregano, bay leaf, crushed red pepper flakes (if using), 1 teaspoon kosher salt, and 1/2 teaspoon black pepper. Stir again. Increase the heat to high and bring the soup up to a boil; this will take about 5–7 minutes.
Step 5: Simmer until lentils are tender
Once the soup reaches a boil, reduce the heat to low or medium-low to maintain a gentle simmer. Partially cover the pot with a lid, leaving it slightly ajar so some steam can escape. Simmer for 30–35 minutes, stirring occasionally, until the lentils are tender but not falling apart.
If at any point the soup looks too thick for your liking, add a splash of hot water or broth. Conversely, if you prefer a thicker, more stew-like consistency, simmer uncovered for the last 5–10 minutes to reduce the liquid slightly.
Step 6: Finish and adjust the seasoning
When the lentils are tender, remove and discard the bay leaf. Stir in the balsamic or red wine vinegar. Taste the soup and adjust the seasoning: add more salt, pepper, or red pepper flakes as needed. The flavors should be bright, savory, and well balanced, with a subtle herbal note from the rosemary.
If you like a slightly creamier texture, you can gently mash a small scoop of lentils against the side of the pot with a spoon and stir them back in. This will naturally thicken the broth without any dairy.
Step 7: Serve with garnishes
Ladle the hot soup into warm bowls. Top each serving with a sprinkle of freshly grated Parmesan, chopped parsley, and a few tiny pinches of finely chopped fresh rosemary, if desired. Finish with a grind of black pepper and a drizzle of good olive oil, if you like.
Serve immediately with slices of crusty bread for dipping. The soup will continue to thicken slightly as it stands; you can loosen leftovers with a little water or broth when reheating.
Pro Tips
- Choose your sausage wisely: Mild Italian sausage gives a classic, family-friendly flavor, while hot Italian sausage adds pleasant heat. A 50/50 mix works beautifully.
- Use green or brown lentils: They hold their shape better than red lentils, which tend to fall apart and make the soup mushy.
- Salt gradually with lentils: Starting with a modest amount of salt and adjusting at the end helps the lentils cook evenly and keeps the flavor balanced.
- Layer flavor with browning: Take time to get good color on the sausage and to toast the tomato paste; these two steps make the broth taste slow-simmered.
- Adjust the texture: For a brothier soup, add extra hot water or broth. For a thicker, stew-like bowl, simmer uncovered at the end and lightly mash a few lentils.
Variations
- Turkey or chicken sausage: Swap in the same amount of Italian turkey or chicken sausage for a lighter version with less fat but still plenty of flavor.
- Tuscan-style with greens: Stir in 3–4 cups chopped kale, chard, or spinach during the last 5–10 minutes of simmering until wilted and tender.
- Smoky vegetarian version: Skip the sausage and use vegetable broth. Add 1–1.5 tsp smoked paprika and 1 extra tablespoon olive oil to replace the richness and smokiness.
Storage & Make-Ahead
This soup keeps and reheats beautifully, making it ideal for meal prep. Let the soup cool to room temperature, then transfer to airtight containers. Refrigerate for up to 4 days. The lentils will continue to absorb liquid, so expect the soup to thicken; when reheating on the stovetop over medium heat or in the microwave, stir in a splash of water or broth to loosen to your preferred consistency, and adjust seasoning if needed.
For longer storage, freeze the soup in freezer-safe containers or heavy-duty freezer bags for up to 3 months. Leave a little headspace for expansion. Thaw overnight in the refrigerator before reheating. Garnishes like Parmesan, parsley, and a fresh drizzle of olive oil are best added right before serving, not before freezing.
Nutrition (per serving)
Approximate values per serving (1/6 of the recipe): about 430 calories, 27 g protein, 36 g carbohydrates, 10 g dietary fiber, 18 g fat (6–7 g saturated), 75 mg cholesterol, and 900–1,000 mg sodium (will vary based on broth, sausage, and added salt). These numbers are estimates and should be used as a general guide only.
