In a large pot, heat 2 tablespoons of olive oil over medium heat. Once shimmering, add the diced onion and sauté for about 5 minutes until it turns translucent and fragrant. Next, stir in minced garlic, diced carrots, and chopped celery, continuing to cook for an additional 3-4 minutes until the vegetables are tender.

Add the cubed russet and sweet potatoes, chopped zucchini, and trimmed green beans into the pot. Follow with the entire can of diced tomatoes and drained chickpeas, combining everything well.

Pour in 4 cups of vegetable broth while seasoning the mixture with dried thyme, smoked paprika, bay leaf, salt, and pepper. Stir everything to combine thoroughly.

Bring the stew to a gentle boil over medium-high heat, then reduce the heat to low and cover the pot. Allow it to simmer for 25-30 minutes, stirring occasionally, until all vegetables are tender.

After the vegetables are tender, stir in roughly chopped kale or spinach, allowing them to wilt for an additional 5 minutes. Before serving, remove the bay leaf and adjust seasoning with lemon juice and additional salt or pepper as needed.