1/4 cup extra-virgin olive oil
1/4 cup red wine vinegar
1 teaspoon dried oregano
3/4 teaspoon fine salt, divided
1/4 teaspoon freshly ground black pepper
1 medium red bell pepper, diced
1/3 cup small-dice red onion
1 pound dry fusilli or rotini pasta
1 (12.5-ounce) jar marinated artichoke hearts, drained and coarsely chopped
4 ounces dry Italian salami, casing removed, diced (about 1 cup)
1 (2.5-ounce) can sliced black olives, drained
8 ounces fresh mozzarella cheese, diced
1/2 cup coarsely chopped fresh Italian parsley
Bring a large pot of heavily salted water to a boil over high heat. Meanwhile, whisk the oil, vinegar, oregano, 1/4 teaspoon of the salt, and pepper together in a large bowl; stir in the bell pepper and onion and set aside.
Add the pasta and cook according to package directions. Drain. Add the hot pasta, remaining 1/2 teaspoon salt, artichokes, salami, and olives to the bowl of dressing. Toss thoroughly to combine. Let sit 20 minutes, stirring occasionally, to allow the pasta to cool and the flavors to combine.
Stir in the cheese and parsley. Taste and season with more salt, pepper, or vinegar as needed.