Sauté the Vegetables:
Heat olive oil in a large pot over medium heat. Add the onion, carrots, and celery. Sauté for 5-7 minutes, or until softened.
Cook the Mushrooms:
Add the mushrooms to the pot and cook for another 5 minutes, stirring occasionally, until they release their moisture and start to brown.
Add Garlic and Seasonings:
Stir in the garlic, thyme, rosemary, salt, and pepper. Cook for 1 minute until fragrant.
Add Beans and Broth:
Add the white beans, vegetable broth, and bay leaf to the pot. Stir to combine. Bring to a gentle simmer and let cook for 20 minutes, allowing the flavors to meld.
Optional Greens:
Stir in the chopped kale or spinach during the last 5 minutes of cooking if desired.
Finish the Stew:
Remove the bay leaf. Stir in the lemon juice for a bright, fresh flavor. Taste and adjust seasoning as needed.
Serve:
Ladle the stew into bowls and garnish with fresh parsley. Serve hot with crusty bread or over rice.