Clean the squid. Cut the pouches into rings and separate the tentacles if large.
Heat the oil in a large, heavy-based pan. Add the squid and cook over a high heat, stirring from time to time, until lightly browned.
Add the onion and garlic to the pan and cook for about 5 minutes, until softened.
Stir in the tomatoes, red wine, water and thyme and bring up to the boil. Cover and simmer very gently for 2 hours.
Season with salt and pepper and eat as it is or use as a base for a fish stew.