Slow-Simmered Lentil and Sweet Potato Soup with Herbs

By Lauren Mitchell, Test Kitchen Director · Reviewed by AislePrompt Editorial · Published 2026-04-11 · Updated 2026-04-11

A deeply comforting soup with earthy lentils, sweet potatoes, and fresh herbs, gently simmered for maximum flavor. This west african-inspired vegetarian ready in about 55 minutes pairs rinsed green lentils, medium, peeled and diced sweet potato, medium, diced onion for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 280 calories and feeds 4, 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 green lentils
• 2 medium, peeled and diced sweet potato
• 1 medium, diced onion
• 2 medium, diced carrots
• 3 cloves, minced garlic
• 4 cups vegetable broth
• 1 tsp dried thyme
• 1 bay leaf
• 1 tsp salt
• 1/4 tsp black pepper
• 2 tbsp fresh, chopped thyme
• 1 tbsp olive oil

Instructions

1. Step 1: Heat 1 tbsp olive oil in a large pot over medium heat. Add diced onion and garlic, and cook for 3 minutes until fragrant. Add diced carrots and sweet potato, and cook for 5 minutes, stirring occasionally.
2. Step 2: Stir in rinsed green lentils, 4 cups vegetable broth, 1 tsp dried thyme, 1 bay leaf, 1 tsp salt, and 1/4 tsp black pepper. Bring to a boil, then reduce heat to low, cover, and simmer for 30 minutes until lentils and vegetables are tender.
3. Step 3: Remove bay leaf. Using an immersion blender, blend half the soup until smooth (or transfer to a blender in batches). Return to pot and heat through. Stir in 2 tbsp fresh chopped thyme and serve hot.