Fill a 6-quart / 5.7 L pot with 4 L / 4 quarts of water, add 1 tbsp kosher salt and bring to a boil over high heat, about 7 minutes. Meanwhile, add the olive oil, red wine vinegar, Dijon, grated garlic, oregano, pepperoncini brine, 1/4 tsp salt and pepper to a 16-oz / 473 ml jar, seal and shake until it looks creamy.
While the water heats, halve the tomatoes, slice the cucumber and red onion, slice the pepperoncini, cut the salami into 1 cm strips, and pat the chickpeas and mozzarella pearls dry with a clean towel.
Add the pasta to the boiling water, stir right away and cook for about 7 minutes, 1 minute short of the package time, until al dente with a slight bite. Drain and rinse under cold water for 30 seconds until no steam rises, then shake well.
Combine the pasta, salami, mozzarella, chickpeas, tomatoes, cucumber, onion and pepperoncini in a 5-quart / 4.7 L mixing bowl. Shake the dressing again, pour it over, add the Parmesan and half the basil, and toss gently until every piece is coated. Cover and chill for 15 minutes.
Taste, add a pinch of salt only if needed, and divide among 4 bowls, about 495 g each. Top with the remaining basil and black pepper.