Cook the pasta to packet directions. Drain well. Place in a large bowl and mix through half the dressing. Leave to cool.
Peel the onion, cut in half and slice thinly. Separate the layers. Cut the tomatoes into quarters then in half crosswise. Remove the skin and seeds from the peppers and cut the flesh into 1 centimetre cubes. Mix the rocket and basil together.
Add the onion, tomatoes, pepper, and olives to the pasta. Mix enough of the remaining dressing through the greens to lightly cost. Mix the remaining dressing into the pasta mixture.
Arrange the greens on a platter. Top with the pasta mixture. Sprinkle seeds over and serve.
Crush and peel the garlic.
Shake all the ingredients together in a screw top jar.