Set a large 6-8 quart saucepot over medium heat. Add the olive oil, chopped onions, celery, carrots, garlic, fresh herbs, crushed red pepper, and 1 teaspoon salt. Sauté to soften for 3-5 minutes, stirring occasionally.
Add the vegetable broth, diced tomatoes, and white beans. Bring to a boil. Lower the heat, if needed, and simmer for 15-20 minutes.
Stir in the chopped kale and broccoli florets. Simmer another 5-8 minutes. Then stir in the lemon juice. Taste, then salt and pepper if needed. Serve hot.
Stored in an airtight container this vegan soup will keep well for up to 5 days in the refrigerator.If you do include cooked chicken then leftovers will keep well for up to 3 days in the fridge.This is an excellent make ahead recipe for freezing, too! Simply allow the soup to cool completely before transferring to a freezer-safe container for up to 3 months.