Paella on the barbecue

Method

1. Fire up a round kettle barbecue with a full basket of coals.
2. Put the prawn heads and shells in a saucepan of water over medium heat and simmer for 15 minutes to obtain a red stock. Strain the stock into a bowl through a sieve, add the saffron and top up with a little water to give you 1.25 litres. Set the stock aside but keep it hot.
3. When the coals are glowing, put a paella pan (with a 32 cm/123/4 in base) on the grill over the coals and add the olive oil – the oil will get hot quickly as a paella pan is quite thin. Add the shallots, garlic, herbs and chicken and season with the sea salt. Stir to soften the shallots and lightly cook the chicken for about 5 minutes.
4. Before you add the rice, rinse it until the water runs clear. Add the rice to the paella pan and stir for 30 seconds to coat the rice in oil, then add the wine and continue to stir for 2 minutes until the rice has absorbed the wine. Add the tomato passata and stir to coat the rice, then add the reserved hot prawn head stock. Bring to the boil and simmer slowly, stirring occasionally, for 5 minutes. Add the mussels and broad beans and stir one last time.
5. Lift the grill flaps up on the barbecue (if it has them) and suspend the paella high off the coals to maintain a slow simmer (or use a brick to prop up the pan). Don’t stir anymore as a light caramelised crust will begin to form under the rice when cooked, called a socarrat, and this is a highly prized element of the dish.
6. After 5 minutes place the prawns on top to steam gently from the heat of the rice. Make sure to turn them after 5 minutes.
7. Soon the rice will have absorbed most of the stock and little steam vents will form. Taste the rice on top to see if it is cooked. Like risotto, it should be al dente, but it won’t be creamy in texture as it isn’t stirred. When you are satisfied, lift the pan off the barbecue and place it on the table with a tea towel (dish towel) over it and rest it for 15 minutes. (This is the perfect time to have a sherry!)
8. Remove the tea towel and divide the paella among serving plates, scraping some of the trophy socarrat crust into each portion. Serve with the lemon wedges for squeezing.