Combine the Poppy Seed Dressing ingredients in a small glass jar and set aside to allow flavours to blend.
Wash the outside of the cantaloupe thoroughly to prevent possible contamination when you slice into it.
Slice the cantaloupe in half, remove seeds, then cut into wedges. Slice down to the rind to create chunks, then slide a sharp knife underneath to remove the rind and release the chunks. Place in a salad bowl.
Add washed, dried and torn arugula leaves and finely diced red onion.
Toss with Poppy Seed Dressing just before serving.