Chop the onion, carrots, celery, and rosemary. If using fresh rosemary, remove the leaves from the woody stems before chopping. Mince the garlic or roast a whole head for a sweeter, caramelized flavor.

Heat the olive oil in a large pot over medium heat. Add the onion and a pinch of salt; cook until soft and translucent, about 5-7 minutes. Stir in the carrots and celery and cook another 5 minutes until they begin to soften. Add the garlic and rosemary and cook 1 minute until fragrant.

Stir in the drained and rinsed white beans, vegetable broth, and water. If using a bay leaf, add it now. Bring the soup to a gentle boil, then reduce heat and simmer for 15-20 minutes to meld the flavors.

Remove the bay leaf (if used). Use an immersion blender to puree about half the soup directly in the pot for a creamy texture while leaving some whole beans for body. If you don’t have an immersion blender, carefully transfer 2 cups of the soup to a blender, pulse until smooth, and return to the pot.

Stir in the lemon juice a little at a time and season with salt and pepper. Taste and adjust acidity—sometimes a touch more lemon really lifts the flavors. If using, stir in non-dairy milk or tahini for a richer mouthfeel.

Ladle the soup into bowls and garnish with chopped parsley, a drizzle of olive oil, a grind of black pepper, and extra lemon wedges.