When you come to the end of a wedge of parmigiano-reggiano cheese, take a tip from the Italian farmwife’s native frugality and save the rind to use later in soups and stocks. It will keep, well wrapped, in the refrigerator for several weeks, or store it in the freezer for longer periods. Then just toss it into the mix for a chicken or vegetable stock, where it will add subtle richness and meaty flavor. When the stock is finished, extract the rind and discard it.
Ditalini are small tube-shaped pastas, as if you took a strand of bucatini and chopped it into half-inch bits. You could substitute elbow macaroni or any other type of small pasta shape here—keeping in mind that this is a soup, so any shape too big to fit on a soupspoon is not advised.
This is a splendid way to announce the first fresh green peas of the season, and if you can find pea shoots, the leafy tops of young pea plants, along with their soft curly tendrils, they make a handsome addition. Lacking pea shoots, you could use watercress, although the flavor is a bit spicier. If you use watercress, we advise changing the quantities—3 cups shucked fresh peas and 3 cups loosely packed watercress should do it.
SERVES 6
10 cups homemade chicken stock (see here)
½ pound, more or less, parmigiano-reggiano rinds (see headnote)
Sea salt
About ¾ pound ditalini
2 cups tender young peas, freshly picked and shucked
4 loosely packed cups pea shoots
Freshly grated zest of 1 organic lemon
Coarsely ground black pepper
½ cup freshly grated parmigiano-reggiano
Combine the chicken stock and parmigiano rinds in a saucepan and bring to a simmer over medium-low heat. Reduce the heat to low. The liquid should just barely bubble up from the bottom; use a flame tamer if necessary. Simmer, uncovered, until the stock is reduced to 8 cups, about 2 hours. Strain the stock and discard the rinds. (This may be done ahead of time; the stock is fine for an hour or so, depending on ambient temperature, but for a longer time, it should be refrigerated.)
When you’re ready to continue with the soup, return the stock to a simmer over medium-low heat. Add salt and the ditalini and cook according to the instructions on the package. (Ditalini should take about 10 minutes.) When the ditalini are almost al dente, add the peas (they will take about 2 minutes to cook).
When the peas are done, add the pea shoots and the lemon zest to the simmering stock. Taste for salt, adjust if necessary, add plenty of pepper and the grated parmigiano-reggiano, and serve immediately.