Empty the flour into a bowl. Add the eggs and oil, knead into a smooth dough using the dough hook on a food processor for approx. 10 mins. Shape into a ball, cover and leave to rest in the fridge for min. 2 hrs.
On a well-floured surface, roll out the dough in batches (approx. 20 x 35 cm) until translucent. Keep separating the dough from the work surface. Dust the pieces of dough with a little flour, roll up loosely, cut into strips approx. 1 cm wide.
Heat the butter in a non-stick frying pan. Add the onion, sauté for approx. 5 mins., add the meat, cook for approx. 5 mins. until all the liquid has evaporated. Place the meat and onions in a bowl. Squeeze out the spinach, add to the meat along with the cheese and eggs, mix, season. Heat the cream in a pan. Add the saffron, season, simmer for approx. 3 mins. Allow the cream to cool slightly, add to the meat.
Cook the tagliatelle in boiling salted water for approx. 2 mins., drain, add to the bowl containing the sauce, mix until the sauce thickens. Serve with parmesan.