Cook your whole-grain pasta as per package instructions and set aside to cool off.
Wash arugula, and depending on size, pluck into bite-sized bits. Cut cherry tomatoes, bell pepper, and cucumber into smaller chunks.
Cut onion into half-moon shapes. Drain mozzarella cheese and slice into cubes.
Coarsely crumble walnuts and tear basil leaves into smaller pieces.
Combine remaining ingredients to create dressing. Optionally, add a crushed garlic clove to the dressing.
Toss all ingredients into a large bowl and incorporate well. Give it a taste and adjust the seasoning if necessary.