Place the chicken thighs skin-side down in a large, cold pan, then turn the heat to medium—I like cast iron here but any heavy-bottomed pot/pan works.

Allow the fat to render and the skin to crisp, without moving the chicken, for 10-12 minutes, until deeply golden and crispy. Flip and cook for another 2 minutes. The chicken should be almost cooked through at this point, but will finish cooking later with the pasta. Transfer to a plate and cover loosely with foil to keep warm.

Reserve about 2 tbsp of the rendered chicken fat in the pan and discard the rest. Add the diced onions and a generous pinch of kosher salt. Stir, then cover and cook for 5-10 minutes over low heat to allow the onions to steam and soften.

Remove the lid, reduce the heat to medium-low, and add the fresh thyme sprigs. Continue cooking for 25-30 minutes, stirring every few minutes, until the onions are deeply caramelized and golden brown.

Stir in the minced garlic and cook for another minute, until fragrant. Add the balsamic vinegar, scraping up any browned bits from the bottom of the pan. Remove and discard the thyme sprigs.

Add the stelline pasta and stir to combine with the caramelized onions, lightly toasting for about a minute.

Pour in the chicken stock and increase the heat to medium. Cook for 2-3 minutes, stirring occasionally. Nestle the chicken thighs on top, skin-side up, making sure the crispy skin stays above the liquid.

Continue cooking uncovered over medium-low heat until the pasta is tender, most of the stock has been absorbed, and the chicken thighs reach an internal temperature of 165°F. If the pasta absorbs the liquid before it's fully cooked, add more chicken stock, a splash at a time, until tender.

Remove the chicken thighs and set aside. Turn off the heat and stir in the heavy cream, finely grated Parmesan, and Worcestershire sauce until the cheese has melted and the pastina is creamy. If the pastina is too thick, loosen it with an additional splash of chicken stock.

Spoon the creamy pastina onto plates and top with the crispy chicken thighs. You can also return the chicken thighs to the pan for presentation before serving onto individual plates. Garnish with freshly minced chives and enjoy!