Bring a large pot of salted water to a rolling boil. Add the tricolor rotini pasta and cook according to package instructions until al dente, about 8-10 minutes.

Drain the pasta in a colander and rinse it under cold water for about 1-2 minutes.

In a small mixing bowl, whisk together the ranch dressing ingredients, then chill in the refrigerator for about 10 minutes.

In a large mixing bowl, combine the cooled tricolor rotini, chopped broccoli, diced cucumber, and halved cherry tomatoes, then toss gently.

Pour the chilled ranch dressing over the pasta mixture and gently stir until evenly coated.

Adjust seasoning with salt and pepper. Cover and let sit in the refrigerator for 1-2 hours before serving.