Blend or process parsley, coriander, chili, garlic, lemon zest and juice until smooth. With motor running, gradually add oil in a thin, steady stream; process until mixture combined. Season to taste and set aside.
Thread a skewer lengthways through the chorizo, then thread on a prawn and alternate so each skewer has 3 pieces of chorizo and 2 prawns.
Heat a lightly oiled barbecue or griddle pan to medium-high heat. Grill the prawn and chorizo skewers for 1 – 2 minutes each side until the chorizo is charred and the prawns are just cooked through. Serve with herb dressing.