This recipe can of course be made with store-bought rapini, which is virtually identical to its wild cousin. Orecchiette is a typical pasta shape for this dish, but you can use any short pasta here. Fusilli or gemelli are good alternatives. This recipe is good either hot or at room temperature.
This first step is optional, but it make the rapini prettier. Bring a large pot of water to a boil and salt it heavily; it should taste like seawater. Set up a bowl of ice water nearby. Boil the rapini for 90 seconds, then plunge into the ice water to stop cooking. This sets the jade green color. Either way, you need the boiling water for the pasta, so you might as well do it.
Once the rapini has been blanched, add the orecchiette and cook until al dente. Use this time to chop the onion, garlic and salami, if using. Drain the pasta and toss with a little olive oil. Set aside.
Heat the 2 tablespoons of olive oil in a large saute pan set over high heat. The moment it begins to smoke, add the onion and toss to combine. Sear the onion until you have some caramelized edges, stirring only every minute or so.
Turn the heat down to medium-high and add the rapini, garlic, chiles and salami. Toss to combine everything. Saute for 2 minutes, then add the pasta and saute another minute, stirring often. Turn off the heat and add the lemon juice and black pepper. You can drizzle a little high-quality olive oil over the dish right when you serve, too.