<ul>
<li>In a large pot, heat olive oil over medium heat.</li>
<li>Add chopped onion and garlic, and saut&eacute; for 3-4 minutes until soft and fragrant.</li>
<li>Stir in carrots, celery, zucchini, potato, and green beans. Cook for another 5 minutes.</li>
<li>Pour in the vegetable broth and diced tomatoes, bring to a boil.</li>
<li>Add thyme, basil, salt, and pepper. Lower the heat and simmer for 15-20 minutes, or until the vegetables are tender.</li>
<li>&nbsp;Add spinach or kale and let it wilt for about 2-3 minutes.</li>
<li>Stir in lemon juice if using, adjust seasonings if needed, and garnish with fresh parsley. Serve hot.</li>
</ul>