1- Dice the lean beef. Peel the clove of garlic, wash and chop finely; wash the parsley, dry with a cloth and chop. Blanch the tomatoes in boiling water, drain, remove the skin, seeds and juice, then chop roughly.
2- Put the oil in a pan with the garlic, add the diced beef and cook on a high flame until the meat is golden on all sides; season with a pinch of salt and pepper, pour in the white wine and allow to evaporate on a high flame, add the tomatoes and chilli pepper.
3- Cook the meat sauce covered for about 40 minutes on a medium heat, stirring occasionally with a wooden spoon; at the end of the cooking time, sprinkle with chopped parsley.
4- Bring a saucepan of salted water to the boil and cook the tagliatelle until they are "al dente"; drain well and add the sauce with the morsels of beef and serve hot, sprinkled as required with grated Parmesan cheese.