Boil water in a large pot and add a pinch of salt.
Add the rotini pasta and cook according to package instructions until al dente.
Drain the pasta and rinse under cold water to stop cooking.
In a large bowl, combine the drained tuna and chopped vegetables.
Add the cooled pasta to the bowl with tuna and veggies.
In a separate small bowl, mix mayonnaise, lemon juice, salt, and pepper.
Pour the dressing over the pasta mixture and toss gently to combine.
Chill the salad in the refrigerator for at least 30 minutes.
Before serving, adjust seasoning to taste.
Garnish with fresh parsley and serve chilled.