Bring a large pot of salted water to a boil. Add the orzo and cook according to package instructions (8-10 minutes). Drain and rinse with cold water.

In a mixing bowl, combine the red and orange bell peppers, red onion, cucumber, and corn.

Add chopped tomatoes, basil, and green onions to the mixing bowl.

Add the cooled orzo to the vegetables and mix together.

In a small bowl, whisk together the olive oil, lemon juice, lemon zest, Dijon mustard, garlic, salt, and pepper until emulsified.

Pour the dressing over the salad and toss to combine. Adjust seasoning if needed.

Serve immediately or refrigerate (dressing separately) for up to four days.