Bring a large pot of salted water to a boil. Add pasta and cook until just al dente. Drain and rinse under cold water to cool the pasta; transfer to a large bowl.
Chop salami, provolone, vegetables, and parsley. Place the prepared ingredients in the bowl with the pasta.
Whisk together olive oil, Dijon, oregano, garlic, sugar, salt, and pepper in a small bowl or jar until emulsified.
Pour the dressing over the pasta and mix-ins, tossing gently to combine. Refrigerate at least 20 minutes to let flavors meld.
Give the salad a final toss, adjust seasoning as needed, garnish with parsley, and serve at room temperature or chilled.
Notes
Make up to 24 hours ahead; store chilled.
Add a splash of extra olive oil or vinegar if the salad dries out after sitting.
Swap meats or cheeses to suit your taste, or make vegetarian by adding chickpeas.
Use short, ridged pasta shapes to trap dressing and mix-ins.