Slow-Cooked Lentil and Vegetable Soup

By Lauren Mitchell, Test Kitchen Director · Reviewed by AislePrompt Editorial · Published 2026-04-14 · Updated 2026-04-14

A nourishing soup made with earthy lentils and seasonal vegetables, simmered until the flavors deepen. This American-inspired soup recipe (vegetarian), ready in about 60 minutes, pairs lentils, carrots, celery for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 220 calories and feeds 6, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

Ingredients

• 1 cup, rinsed lentils
• 2 medium, diced carrots
• 2 stalks, diced celery
• 1 medium, diced onion
• 2 cloves, minced garlic
• 1 cup diced tomatoes
• 4 cups vegetable broth
• 1 tsp dried thyme
• 1 bay leaf
• 1 tsp salt
• 1/2 tsp black pepper
• 1 tbsp lemon juice

Instructions

1. Step 1: In a large pot, combine 1 cup rinsed lentils, 2 diced carrots, 2 diced celery stalks, 1 diced onion, 2 minced garlic cloves, and 1 cup diced tomatoes. Add 4 cups vegetable broth, 1 tsp dried thyme, 1 bay leaf, 1 tsp salt, and 1/2 tsp black pepper.
2. Step 2: Bring to a gentle simmer over medium heat, then reduce heat to low. Cover and cook for 45 minutes, or until lentils are tender.
3. Step 3: Remove bay leaf, then stir in 1 tbsp lemon juice. Simmer uncovered for 5 minutes to meld flavors.
4. Step 4: Adjust seasoning with additional salt or pepper if needed, and serve hot.