Cook the pasta in a large pot of salted boiling water according to package instructions, adding the broccoli florets to the pot of boiling water during the final 30 seconds of cooking. Drain and rinse under cold water. Set aside to cool completely.
In a large bowl, combine cooked pasta, broccoli, peas, red bell pepper, cucumber and green onion.
In a separate small bowl, prepare the dressing by whisking together the mayonnaise, lemon juice, basil, garlic, sugar, ½ teaspoon of salt and ¼ teaspoon of pepper.
Pour half of the dressing over the salad and gently toss to coat. Taste and season with additional salt and pepper, if necessary. Store the remaining dressing in an airtight container or jar in the refrigerator.
Cover the salad and refrigerate for at least 2 hours, or overnight.
Just before serving, toss with reserved dressing to moisten. Taste and season with additional salt and pepper, if necessary. Garnish with fresh parsley.
Notes
Plan ahead and make sure that you allow at least 2 hours for the salad to "marinate" in the dressing and the flavors to come together.
Rinse the pasta and broccoli under cold water to stop the cooking process, cool it down quickly, and remove starches so that the noodles don't stick to each other.
Thaw the peas quickly by placing the frozen peas in a colander. When you drain the pasta and broccoli florets, pour the hot pasta and water over the peas in the colander. They will thaw almost instantly when the hot pasta hits them!
Grate the peeled garlic clove on a microplane so that you have all of the great garlic flavor in your dressing without any big chunks.