In a large pot, heat the olive oil over medium heat. Add the diced onion and sauté until translucent, about 5 minutes.
Stir in the minced garlic and cook for an additional minute until fragrant.
Add the diced potatoes, broth, thyme, and rosemary to the pot. Bring to a boil, then reduce heat and let simmer for 15-20 minutes, or until the potatoes are tender.
Stir in the chopped kale or spinach and cook for another 5 minutes until wilted.
Season with salt, pepper, and lemon juice. Adjust seasoning to taste.
Serve hot, garnished with fresh parsley.