Process all ingredients in a blender until smooth (except for the reserved vegetables). Season with salt and pepper, to taste.
Chill for 3 to 4 hours.
Serve in small jars or bowls. Garnish with the reserved vegetables and drizzle a little more olive oil on top.
Notes
For another take on how to make this dish, if you'd prefer a bit more texture in the finished product or if you simply don't have a blender, you can try the old method of grinding the ingredients in a mortar.
To store any leftovers you might have, just seal up the serving jars with a lid or plastic wrap and place them in the fridge. They'll keep for 4 to 5 days like this and even longer if you freeze them.