Method

• 1.
  Place the tomato paste, stock and prawn heads in a large saucepan over medium heat. Simmer for 10 minutes.
• 2.
  Strain stock into a bowl, discarding prawn heads. Keep the stock warm.
• 3.
  Heat a barbecue chargrill to high heat and place a large paella pan (we used a 30cm round pan) or large deep frypan on the grill. Alternatively, heat the pan over high heat.
• 4.
  Add the oil, onion, garlic, capsicum, paprika, chorizo and parsley, and cook, stirring, for 4-5 minutes until onion begins to soften and chorizo starts to brown. Add the rice and stir until coated then spread evenly over the base of the pan. Pour in 1.2L stock.
• 5.
  Reduce heat to medium-low and cook, without stirring, for 20-25 minutes until the rice is three-quarters cooked. Increase heat to medium, scatter over peas and place the clams and prawns evenly over the rice (make sure you push them down into the rice so that they cook) and cook for 7-8 minutes until clams have opened and prawns are cooked. Discard any unopened clams.
• 6.
  If paella gets a little dry top up with remaining stock. You want to form a caramelised crust on the bottom of the rice. Scatter over extra parsley and serve with lemon and aioli.