Slow-Simmered Vegetable Soup with Lemon and Thyme

By Lauren Mitchell, Test Kitchen Director · Reviewed by AislePrompt Editorial · Published 2026-04-20 · Updated 2026-04-20

A light, herbaceous soup featuring tender vegetables simmered in a fragrant broth, brightened with lemon zest and thyme. This general-inspired soups ready in about 45 minutes pairs medium, peeled and diced carrots, stalks, finely chopped celery, medium, diced onion for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 120 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

• 2 medium, peeled and diced carrots
• 2 stalks, finely chopped celery
• 1 medium, diced onion
• 1 medium, diced zucchini
• 1 cup, halved cherry tomatoes
• 2 tsp fresh, chopped thyme
• 1, zested and juiced lemon
• 4 cups vegetable broth
• 2 tbsp olive oil
• 1/2 tsp salt
• 1/4 tsp black pepper

Instructions

1. Step 1: Heat 2 tbsp olive oil in a large pot over medium heat. Add 1 diced medium onion and cook for 5 minutes until translucent.
2. Step 2: Add 2 diced medium carrots, 2 finely chopped celery stalks, and 1 diced medium zucchini. Cook for 5 minutes, stirring occasionally.
3. Step 3: Stir in 4 cups vegetable broth, 2 tsp fresh chopped thyme, 1/2 tsp salt, and 1/4 tsp black pepper. Bring to a gentle simmer and cook for 20 minutes.
4. Step 4: Add 1 cup halved cherry tomatoes and cook for 5 minutes until vegetables are tender.
5. Step 5: Remove from heat and stir in 1 lemon's zest and juice. Adjust seasoning and serve hot.