Easy paella

INGREDIENTS

• 1 tbsp olive oil
• 1 onion , chopped
• 1 tsp each hot smoked paprika and dried thyme
• 300g paella or risotto rice
• 3 tbsp dry sherry or white wine (optional)
• 400g can chopped tomatoes with garlic
• 900ml chicken stock
• 400g bag frozen seafood mix
• juice ½ lemon , other half cut into wedges
• handful flat-leaf parsley , roughly chopped