1. Drain the beans from the water they’ve soaked in overnight.

2. Half fill a cooking pot with water and add the beans. Bring to a boil over high heat. Cook for 3-4 minutes and then drain beans in a strainer.

3. In a medium-sized cooking pot add the olive oil and heat over medium-high heat. Add the onion and garlic and cook until softened and golden in color.

4. Add the beans along with 1.5 liters of water (or 1 liter of water + 500 ml vegetable stock) and bring to a boil. Then reduce heat to medium-low and with the lid partly open, simmer for about 2 hours or until beans are completely soft.

5. Add the celery and carrot and season with salt and pepper. Continue simmering until the soup thickens. Then add lemon juice and zest and cook 2 minutes more. Remove from heat.

6. Instant Pot: Saute onion and garlic in olive oil. Add all ingredients with 1.5 liters water. Cook on manual 20 minutes. Release pressure, finish with lemon zest + juice.

7. Slow Cooker: Saute onion and garlic separately. Add to cooker with remaining ingredients except lemon. Cook 8 hours on low or 4 on high. Add lemon at the end and cook 5 minutes more.