Bring a large pot of salted water to a rolling boil over high heat. Add the rotini pasta and cook according to package directions, usually about 8–10 minutes, until al dente. Drain the pasta and rinse it under cold water.

While the pasta is cooking, wash and dice the cucumber and bell pepper into bite-sized pieces. Slice the cherry tomatoes in half and finely chop the onion. Combine in a large mixing bowl with the chickpeas.

In a small bowl or jar, add olive oil, red wine vinegar, Dijon mustard, minced garlic, oregano, salt, and pepper. Whisk or shake until well combined.

Once the pasta is cooled, add it to the vegetable mixture. Pour the dressing over everything and gently toss together until evenly coated.

Cover the bowl and chill the pasta salad in the refrigerator for at least 15–30 minutes.