Cook the pasta in boiling salted water until al dente, about 8-10 minutes. Drain and rinse under cold water.

In a food processor, blend basil leaves, pine nuts, parmesan, garlic, lemon juice, olive oil, salt, and pepper until smooth.

In a bowl, combine pasta, pesto, tomatoes, mozzarella, onion, pepperoncini, and parsley. Mix gently until evenly coated.

Taste and adjust seasoning with additional salt, pepper, or lemon juice as needed.

Cover and refrigerate the salad for at least 30 minutes before serving.