Toast the Farro: In a large pot over low-medium heat, melt the butter. Once melted, add the farro and toast for a few minutes until it turns golden brown. Keep an eye on it to avoid burning. Once toasted, remove from the pot and set aside.

Sauté the Vegetables: In the same pot, add a splash of olive oil over medium heat. Sauté the chopped celery, onion, garlic, carrots, and sweet potato for a few minutes until slightly softened. Season with salt, pepper, and herbs de provence.

Simmer the Soup: Pour in the stock and water, bringing the mixture to a bubble. Then, reduce to a simmer and add the toasted farro and green beans. Let everything simmer on low-medium heat for about 15 minutes, or until the vegetables and farro are tender.

Finish and Serve: Squeeze in some fresh lemon juice to taste and adjust the seasoning with more salt or pepper if needed. Ladle the soup into bowls, topping with fresh dill or basil and a drizzle of olive oil.