3/4 cup grated parmigiano-reggiano cheese, plus more for garnish
1/4 cup part-skim ricotta cheese
1/2 pound orecchiette pasta
High-quality extra-virgin olive oil, for finishing (optional)
A large saucepan of salted water should be brought to a boil. Prepare a bowl of icy water with plenty of salt. After one to two minutes in the boiling water, drain the broccoli rabe and quickly submerge it in the salted ice water. By doing so, the broccoli rabe will maintain its gorgeous green color and won't be overcooked.
Chop the broccoli rabe finely after draining and pressing out any extra water. In the bowl of a food processor, add the broccoli rabe and pulse until coarse paste forms. Purée until smooth after including the Parmigiano and pistachios. You probably need to add additional salt after tasting and adjusting the seasoning. Pulse the ricotta in with the addition. Reassess the seasoning; it should be full-flavored, just a touch bitter, and creamy all at once. Place aside.
Large saucepan of salted water should be brought to a boil. Cook the pasta for 1 minute less than the recommended cooking time on the package (if you're preparing it directly after making the pesto, just use the water from blanching the broccoli rabe).
Put the pesto in a sizable skillet with about 1 to 1 1/2 cups of the pasta cooking water, and heat over medium-high while the pasta is cooking. Drain the pasta and then add it to the pesto in the skillet when it's done. Add salt to taste and stir well to mix. Cook for 1 to 2 minutes or until the sauce is creamy and well cooked. Remove from the heat, if preferred, and mix vigorously before adding 1 to 2 tablespoons of olive oil. Add additional Parmigiano as a garnish.