Fresh Tuna And Peas

• 1 onion (finely chopped)
• 1 clove garlic (finely chopped)
• 650 gr tomatoes pear shaped
• 525 gr tuna steaks in (cut)
• 375 gr green peas (frozen)
• 60 ml olive oil
• 2 gr parsley
• 1 gr salt
• 1 gr pepper