In large saucepan, heat the stock and water until it reaches a simmering point.
In another saucepan, heat the olive oil. Stir in the onion and leek, and cook for 5-6 minutes, or until the onion has softened.
Add the carrots, celery, and garlic, and cook over medium hear, stirring often, for 5 minutes. Add the potatoes and cook for a further 3 minutes.
Add the veggies to the stock and stir well. Add the bay leaf, thyme, and season with salt and pepper. Bring to the boil, then reduce the heat slightly, and leave to cook for 10-12 minutes more.
Stir in the peas, if fresh, and the zucchini, and simmer for 5 minutes. Add the frozen peas, if using, and the chopped tomatoes. Cover the pan, bring slowly to the boil, then simmer further for 5 minutes.
Stir in the beans and simmer for 10 minutes. Adjust salt and pepper, as needed, and simmer for a further 5 minutes.