Finely dice the red onions, then dice the chicken and chorizo into chunks.
Add to a mixing bowl with the diced red onions, peppers, peas, tomato puree, rice, smoked paprika and thyme.
Grate the stock cube over the top of the mix.
Preheat the oven to 180ºC.
Pour the rice mix into a 10 x 15 inch baking tray and pour over the water.
Give it a mix then cover with tin foil and place into the oven for 40 minutes.
After 30 minutes, remove the foil, give the rice a mix, place the prawns on top and place back into the oven uncovered to cook for a further 10 minutes.
Serve with a wedge of lemon and parsley.
