One Pot Pantry Pasta

• 2 tbsp extra virgin olive oil (onion infused, if you have)
• 2 cloves garlic, crushed
• 1 vegetable salt-reduced stock cube
• 800 g tins diced tomato
• 200 g frozen peas
• 300 g wholemeal penne pasta
• 420 ml water
• 100 g parmesan, to serve (optional)