1. First prepare the tomatoes: bring a large pan of water to the boil and get a bowl with iced water ready. Cut crosses in the base of the tomatoes with a serrated knife and drop them into the boiling water for 10 seconds. Drain them with a slotted spoon into the iced water and drain the water immediately. Peel the skins off tomatoes, cut each in half horizontally and scrape out the seeds with a small spoon. Set the tomatoes aside and empty the pan they were boiling in.
2. Rinse the lentils with plenty cold water and place them in the tomato pan with 3 cups of water, bay leaves, tomato vine if using, and half the thyme sprigs (tied with kitchen string for convenient fishing out later). Bring it to the boil, reduce the heat and simmer, covered, for 20 minutes. Take the pan off the heat and leave to cool or for at least 30 minutes, then drain the lentils and remove the vine and the herbs.
3. Slice the chorizo and place the slices in a large dry frying pan or a wok. Place it over medium heat for about 10 minutes, flipping the sausage occasionally, until the chorizo is crisp and the fat has rendered. Remove the chorizo with a slotted spoon and add the onions and garlic to the pan. Cook stirring for 5 – 10 minutes until it softens.
4. Add the tomatoes to the pan and turn the heat up slightly so the liquid cooks off without the tomatoes dissolving; halve any bigger pieces with a spoon whilst stirring. When the liquid is almost gone, add the lentils and chorizo into the pan. Sprinkle generously with salt, add the tomato puree, ground caraway, smoked paprika and red pepper flakes and cook over high heat, stirring, to get rid of any liquid brought in with the lentils.
5. Taste for seasoning and add half the chopped parsley. When the consistency is to your liking (you might prefer it more soupy in which case add some water instead of cooking it off), spoon the lentils into serving bowls and sprinkle with the grated cheese and extra parsley.
6. Serve immediately, with plain rice or warmed tortillas and plenty of green salad.