For the broth, heat the olive oil in a large heavy-bottomed stockpot and sauté the spring onions until caramelized. Add stock, increase heat and reduce by ⅓. Return broth to a simmer and add celery, carrots, garlic, shiitakes and thyme and let simmer on low heat for an additional 30 minutes. Strain the broth through a fine-mesh sieve. Season with vinegar, miso and salt, to taste. To add a depth of flavor, add a dash of fish sauce (optional).

For the gnudi, line 2 baking sheets with parchment paper. In a large mixing bowl, combine ricotta, Parmesan, eggs, melted butter, chopped herbs and salt. Mix until smooth and ingredients are incorporated. Add flour to the cheese mixture 1 cup at a time, using your hands or a rubber spatula to mix. Form the dough into a ball while in the bowl and then transfer to a floured surface. Divide the ball into 4 equal balls. Shape each piece by rolling it back and forth with the palms of your hands into a round “rope” approximately 1 inch wide by 16 inches long. With sharp kitchen shears, cut each rope into 1-inch pieces and place them on the parchment paper.

To serve, reheat the broth and cook the gnudi right before you plan to eat. Bring a large pot of salted water to boil. Cook gnudi in 4 batches. Once the gnudi float, let them cook for 30 additional seconds, then pull them out using a strainer or slotted spoon and place them on the other lined baking sheet. This will go quickly.

Divide broth and gnudi among 4 to 6 warm shallow bowls. Top with torn parsley and freshly shaved Parmiggiano-Reggiano.