In a slow cooker, combine the vegetable broth, kidney beans, black beans, diced tomatoes with juices, carrots, celery, onion, garlic, thyme, oregano, smoked paprika, bay leaf, salt, and pepper.
Stir the mixture well to combine all the ingredients.
Cover the slow cooker and cook on low for 6-8 hours or on high for 3-4 hours until the vegetables are tender.
About 15 minutes before serving, stir in the chopped spinach and lemon juice.
Remove the bay leaf before serving. Taste and adjust seasoning if necessary.
Serve hot and enjoy your hearty vegetable bean soup!
Notes
Feel free to add other vegetables or spices according to your preference.