In a large pot of salted boiling water, cook pasta until al dente, rinse under cold water, drain and mix with a tsp of olive oil.
Add all of the dressing ingredients to a small mixing bowl and whisk well. Season with salt and pepper to taste then store in refrigerator until ready to serve.
Pour the vinaigrette over the spaghetti and vegetables. Add the feta, basil and olives and toss lightly. Set aside for 30 minutes to let the flavors combine. Serve at room temperature.