Heat olive oil in a large pot over medium heat.
Add onion, carrots, and celery. Cook for 5–6 minutes until softened.
Stir in garlic, zucchini, and cabbage. Cook for 2 minutes.
Add tomatoes, chickpeas, lentils, grain, vegetable broth, thyme, oregano, salt, and pepper.
Bring to a boil, then reduce heat and simmer for 30–35 minutes, or until the grain is tender.
Stir in spinach or kale and cook for 2–3 minutes until wilted.
Add lemon juice and adjust seasoning if needed.
Serve hot.
