Cannellini, Pancetta & Lemon Pasta e Fagioli

4 ounces any small dried pasta, such as rotelle no. 54, small shells, or ditalini
3 tablespoons extra-virgin olive oil
6 ounces pancetta, diced
2 bunches, about 1 pound rainbow chard or spinach, stems trimmed and finely chopped, leaves coarsely chopped
2 yellow onions, finely diced
4 celery stalks, finely chopped
2 carrots, finely chopped
6 garlic cloves, finely chopped
8 sprigs thyme, stemmed
2 bay leaves
1 ¼ teaspoons kosher salt
2 quarts chicken stock
freshly ground black pepper
2 15 ounce cans cannellini beans, drained and rinsed
1 Parmigiano-Reggiano rind, optional, plus finely grated Parmigiano-Reggiano for sprinkling
juice of 2 lemons

In a Dutch oven or large heavy-bottomed saucepan over low heat, warm the olive oil. Add the pancetta and sauté until lightly browned, about 5 minutes. Stir in the chard stems, onions, celery, carrots, garlic, thyme, and bay leaves and season with the salt and pep- per. Cook gently, stirring often, until softened but not brown, 12 to 15 minutes.
Turn the heat to medium and add the chicken stock, beans, pasta, and Parmigiano rind (if using) to the pan. Bring to a simmer, stirring occasionally, and cook until the pasta is just al dente (likely a bit longer than the package instructions because you’re simmering, not boiling, in the stock).
Discard the bay leaves and Parmigiano rind. Stir in the chard leaves until they’ve wilted. Add the lemon juice and adjust the seasoning if needed.
Serve the pasta hot and steamy with a sprinkling of more Parmigiano.