In a medium saucepan, heat up olive oil on medium temperature and add onion. Sautee onion for 2-3 minutes, or until translucent.
Add green peas, potatoes, crushed garlic cloves, tomato puree and water. Optionally, thyme. Cover with tempered lid and leave to cook on medium temperature.
Stir occasionally and check if more liquid is needed. Cook for 25 minutes. The potatoes should easily break apart. Season with salt and pepper and serve.