Heat the olive oil in a large pot over medium-low heat.

Add the sliced leeks and a pinch of salt. Cook slowly, stirring occasionally, for about 20–25 minutes, or until the leeks are soft and golden brown. (If they start to brown too quickly, lower the heat.) The goal is to caramelize the leeks and bring out their natural sweetness.

Once the leeks are golden, add the diced onion to the pot and stir. Chop the garlic cloves and add them in, cooking for five to 10 minutes, until the onions are softened and fragrant.

Dice the potatoes and add them to the pot, stirring to combine with the leek mixture.

Pour in half the chicken stock, then season with salt and white pepper. Add the thyme and bay leaves in a mesh bag for easy removal. To enhance flavor, make a small incision in each bay leaf.

Cover the pot, reduce the heat, and let the mixture simmer for about 35 minutes, until the potatoes are tender.

Remove the bay leaves and thyme bag.

Use an immersion blender to puree the soup until smooth. (If using a regular blender, carefully blend the soup in batches.)

When the soup is smooth and creamy, add the marrow bones and boneless flanken for extra richness.

Pour in the remaining chicken stock, add enough water to fill the pot, and give everything a good stir.

Place the pot back on the stove over medium-low heat.

Stir the soup and let it simmer for another one to two hours, until the meat is tender and the flavors have melded.

Ladle the soup into bowls and garnish with freshly chopped chives or parsley and a sprinkle of veggie coating crumbs for a bit of crunch. For added richness, drizzle a little extra virgin olive oil.

Optional: Serve with cooked mini bow-tie pasta for extra texture.