In a large pot, warm the oil over medium heat. Add the onion, carrots, celery and 1 teaspoon salt and cook until softened, about 5 minutes. Add the garlic, fennel seeds, oregano, and red pepper flakes (if using) and cook for 30 more seconds.
Add the tomato paste and stir to coat the vegetables and spices. Cook for 2 more minutes, stirring occasionally, to caramelize the tomato paste.
Stir in the water, beans, tomatoes, potatoes, farro and remaining 1 teaspoon salt. Bring to a boil over high heat, then cover and reduce the heat to medium-low to maintain a rapid simmer. Cook for 20 minutes, stirring halfway through.
Remove the lid, give it one more stir, and simmer rapidly for 5-10 more minutes (uncovered) or until the farro is cooked through (if farro is taking longer and water level looks low, just add more water).
Turn off the heat and stir in the kale until wilted. Served drizzled with olive oil and sprinkled with parmesan and black pepper.