Drain the soaked cannellini beans and place them in a large pot with fresh water. Bring to a boil over medium heat for 3-4 minutes, then drain and set aside.

Heat 3 tablespoons of olive oil in a medium pot over medium heat. Add the chopped onion and minced garlic, sauté for 5-7 minutes until soft and golden.

Add the drained beans to the pot with the onion and garlic. Stir in 4 cups of water or vegetable stock, along with the sliced carrot and chopped celery. Bring to a gentle boil.

Reduce the heat to medium-low and cover slightly. Simmer for 1.5 to 2 hours, stirring occasionally until beans are tender.

Season with salt and pepper to taste. Squeeze in the lemon juice and add its zest, cooking for an additional 2 minutes. Serve garnished with fresh herbs and crusty bread.