Over medium-high heat in Dutch oven or pot, with the olive oil, sauté onions, carrots, celery, green pepper, salt and black pepper for 10 minutes.
Turn down heat to medium, add garlic and sauté for 1 minute more.
Add broth, water, tomatoes, parsley, rosemary, crushed red peppers, oregano, fennel seed, bay leaf, farro and lentils; stir, cover with lid and cook for 25 minutes.
Remove lid, add beans, stir, cover again with lid and cook for another 35 minutes.
Remove lid, spinach and lemon juice and cook for 1 minute.
Disregard bay leaf.
Serve in bowls and garnish with fresh chopped basil.