½poundpastina(Acini de pepe or stelline. See notes.)
⅓cupgrated Parmesan cheese(plus extra for serving)
Add 2 tablespoons of olive oil to a soup pot and place it over medium heat. Use a long spoon to push the oil around the bottom of the pan so it completely covers the bottom. Heat the oil until it's sizzling.
When the oil is sizzling, pat the chicken breasts dry with paper towels and add them to the pot with tongs. In a tiny bowl, stir together ¼ teaspoon of garlic, ⅛ teaspoon of black pepper, and ⅛ teaspoon of salt. Season the chicken with this mixture. Let the chicken sear for five minutes on the first side, until it's golden brown.
Wear oven mitts while using tongs to flip the chicken over (the oil may splash). If the chicken is sticking to the pan, use the tongs to push under the chicken to separate it from the pan. When the chicken is flipped over, pour one cup of the chicken stock over it and cover the pot. Let the chicken simmer gently over medium heat for seven minutes.
While the chicken is simmering, prepare the vegetables. Peel half an onion and chop it. Rinse the celery, scraping off any dirt, and trim off the ends. Cut the celery into small pieces (dice). (Cut a stalk in half the short way, then slice each of those pieces in half the long way. Then cut into small pieces.) Rinse the carrots and peel them. Trim off the ends. Cut the carrots into small pieces like the celery.
When the chicken has simmered for seven minutes, use tongs to remove the chicken to a large bowl to sit for a couple minutes to cool. (If you have a stand mixer, place the chicken in the bowl of the stand mixer.) You will be shredding the chicken after you get the vegetables going in the pan (see the next step).
While the chicken is cooling off a bit, add the onions, carrots and celery to the pot over medium-high heat and give them a stir. Sauté the vegetables, stirring occasionally, until the carrots and celery are soft. It could take 15 minutes. (You want to make sure you don't have crunchy vegetables in your soup.) If the liquid evaporates during this time, you can add a little stock to the pan, so the veggies don't burn.
While the vegetables are cooking, shred the chicken. The easiest way is to use a stand mixer with a paddle attachment to shred the chicken on a low setting. If you don't have a stand mixer, use two forks to shred the chicken. The chicken should be cooked through, but if it seems slightly undercooked, it will finish cooking later in the soup.
When the vegetables are tender, add the rest of the chicken stock and 3 cups of water to the pot. Stir in ⅛ teaspoon of black pepper. Cover the pot, increase the heat to high, and let the soup come to a boil.
When it is boiling, add the pastina to the pot. Lower the heat slightly, give the pasta a stir, and boil it for 10 minutes, or until al dente. Do not drain it. (Acini de pepe needs the 10 minutes, but stelline may cook faster.)
After 10 minutes, stir in the shredded chicken and ⅓ cup grated Parmesan. Lower the heat and let the pot simmer for a couple minutes until the chicken is heated through. Taste to see if any additional salt is needed. (It will depend on how much salt was in your chicken stock.)
Serve immediately by ladling some soup with pastina into each bowl. Sprinkle Parmesan (or Romano) on each serving. Any pastina left in the pot will absorb the broth quickly, so use a slotted spoon to remove the pastina to a separate container so it can be refrigerated later.
Store leftover pastina separately from the broth. Refrigerate each for up to four days. To reheat, add some of the broth to the pastina in a bowl and heat, covered loosely with wax paper, in the microwave. If you run out of soup broth for leftovers, you can add some chicken stock to the pastina or serve it with butter and cheese.
The leftovers also freeze well. Freeze the pastina and broth separately.
Pastina is tiny pasta. It cooks up into a large amount, so you should not need more than ½ a pound here, even if you're used to cooking 1 pound of pasta. You can even use just ¼ pound of pastina, if you want the soup to have a higher ratio of broth to pasta.
Once cooked, the pastina will quickly absorb the liquid in your pot. Serve the soup immediately, then use a slotted spoon to place any leftover pastina in a separate container from the broth.
If you want to make the soup earlier in the day to serve later, store the shredded chicken separately from the soup in the refrigerator, and don't cook the pastina until just before you are ready to serve the soup. Heat the soup in the pot until boiling, add the pastina, and cook it for 10 minutes. Then, stir in the chicken and Parmesan.
This recipe makes 8 standard servings, or 6 generous servings.