Griddled artichoke and red onion paella

Name: Griddled artichoke and red onion paella
Ingredients: 4 tbsp vegetable oil; 3 red onions, finely sliced; 2 garlic cloves, crushed; 400g/14oz paella rice, such as calasparra; 1 tsp ground turmeric; 1 tsp smoked paprika; 800ml/1 pint 7fl oz hot vegetable stock; 1 tsp finely chopped fresh rosemary; 200g/7oz cherry tomatoes; 150g/5½oz fresh peas; 125ml/4fl oz good quality extra virgin olive oil, preferably spanish; 1 tbsp chopped fresh parsley, to serve; 1 x 400g/14oz can artichoke hearts in water, drained and rinsed