Whisk together the olive oil, sesame oil, parsley, Tabasco sauce, minced garlic, tomato sauce, chilli paste, salt, pepper and lemon juice in a mixing bowl. Set aside about 1/3 of this marinade to use while barbecuing.
Place the prawns in a large, resealable plastic bag or a bowl. Pour in the remaining marinade and seal the bag/cover the bowl. Refrigerate for 2 hours.
Preheat the BBQ for high heat. Thread prawns onto skewers, piercing once near the tail and once near the head. Discard marinade.
Lightly oil the barbie. Cook prawns for 2 minutes per side until opaque, basting frequently with reserved marinade.