Heat a tin of chopped tomatoes with some vegetable stock, as little or as much as you like but enough to be able to cook some pasta in. Once simmering add some pasta shapes and cook until al dente. Season to taste. Add a large dollop of sour cream before serving.
You can vary this base recipe in lots of ways. Add herbs, dried or fresh, chilli flakes for a kick. Sauté chopped onion, bacon or garlic before adding the tomatoes and stock. Add vegetables for a more substantial meal.
Thanks to my friend Viv for the idea.