Prepare Salami: Remove the skin from the salami and cut it into thin strips.
Cook Onions: Warm a large pan on high heat, add a generous amount of EVOO and a splash of water, then add the onions. Cook for about 5 minutes, stirring occasionally.
Boil Pasta: Fill a large pot with water and bring it to a boil. Add 1 tbsp of rock salt, then add the penne, stirring occasionally to prevent sticking. Cook according to packet instructions.
Add Salami: When the onions are caramelized, add the salami strips, stirring to avoid burns.
Simmer Sauce: Stir in the passata, reduce heat to medium, season with salt and pepper, and let simmer for about 5-7 minutes.
Combine Pasta and Sauce: Once the pasta is al-dente, strain it, reserving a mug of pasta water. If the sauce has been removed from heat, reheat it on a low setting, add the pasta, and combine well. If dry, add a bit of the reserved pasta water.
Serve: Ladle pasta onto plates, top with sauce, more torn basil leaves, and a generous amount of pecorino cheese.