Italian Tuna Pasta Bake

• 680 g tomato basil pasta sauce
• 3 cup vegetable stock
• 100 g spinach
• 100 g Kalamata olives, pitted
• 150 g jar red peppers, sliced
• 1 cup green peas, frozen
• 425 g can tuna, in oil
• 400 g wholemeal penne pasta
• 75 g Greek feta, crumbled
• 0.25 cup fresh basil leaves