Speedy tuna pasta salad - Good Food Middle East

Ingredients

• 2 x 220g packs ready-cooked pasta (we used Dolmio Express), or 440g leftover cooked penne (about 200g dried)
• 100g can tuna in oil
• 400g can cannellini beans, (borlotti or butterbeans are also good)
• 1?2 red onion, finely chopped
• zest and juice 1 lemon
• large handful parsley