Cook the whole grain pasta according to package instructions. Drain and rinse under cold water to cool.

In a large mixing bowl, combine the cooked pasta, cherry tomatoes, cucumber, bell pepper, spinach, and red onion.

In a small bowl, whisk together olive oil, lemon juice, dijon mustard, minced garlic, salt, and black pepper.

Pour the dressing over the pasta salad and toss to combine. Top with feta cheese and parsley if desired. Serve immediately or chill in the refrigerator for 30 minutes before serving.