Rinse and slice the leek in half lengthwise. Slice it across into small pieces and rinse them well in a colander. Alternatively you can add them to a bowl with cold water and all the sand and grit will fall to the bottom. Gently scoop them out and dry well on a tea towel.
Heat up a medium soup pot on low flame. Add a lug of olive oil and the sliced leeks with a pinch of sea salt. Give it a good stir and sauté for 5 minutes until it starts to wilt.
Stir in the carrots and cook an additional 5 minutes then add the farro. Toss to coat in the oils and toast for a few minutes.
Add the dry oregano, bay leaf, thyme, Sage and fresh oregano sprigs.
Pour in the water or vegetable stock, give everything a good stir and bring to a simmer. Add the Parmesan rind and cook together for 15 minutes.
Add the crushed tomatoes to the pot together with the zucchini. Simmer another 15 minutes or until the farro is cooked through but still a little al dente.
Rinse the cannellini beans if using a canned variety and add them to the soup.
Remove from heat and taste. Adjust seasonings with the sea salt then add the fresh spinach or kale. Give it a stir so the spinach will wilt from the steam. If using kale I would cook it an extra couple of minutes as it needs a little extra time to soften.
Ladle into bowls and serve with a drizzle of olive oil and garnished with the fresh chives and blossoms or whatever fresh herbs you have on hand.