In a spacious pot, warm olive oil over medium heat until it’s shimmering.
Add diced onion, garlic, carrots, and celery. Cook for 5–7 minutes until vegetables are soft and fragrant.
Stir in white beans, vegetable broth, bay leaf, thyme, rosemary, salt, and pepper. Bring to a gentle boil.
Reduce heat and let the soup simmer uncovered for 20–25 minutes to develop flavor.
For a creamier texture, blend part of the soup using an immersion or regular blender, then return to the pot.
Stir in kale or spinach (if using) and simmer for 5 more minutes until wilted. Add lemon juice and adjust the seasoning to taste.
Ladle into bowls and top with nutritional yeast, red pepper flakes, or a swirl of cashew cream if desired.