Prepare the bolognese by heating the olive oil in a large saucepan over a medium heat for 1 minute. Add the onions with a little salt and sweat them for 5 minutes, stirring occasionally. Stir in the minced garlic and stir well, cooking for a further 2-3 minutes.
Increase the heat and add the mince, browning well and stirring to break the meat up. Once browned, stir in the chopped tomatoes, then the stock and red wine and bring to the boil; the sauce will look quite thin at this point but it will thicken as it reduces. Reduce the heat to a simmer and add the bay leaf and dried oregano.
Cook for 45-50 minutes uncovered until the sauce has thickened, making sure to stir occasionally. Once the sauce is ready, adjust the seasoning and keep warm.
Cook the tagliatelle in a large saucepan of boiling salted water according to packet instructions until al dente; usually 8-10 minutes. Drain well and spoon divide between 4 serving bowls. Spoon the sauce on top and then sprinkle over the grated parmesan. Garnish with thyme sprigs and a little freshly ground black pepper before serving.
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.