Heat the oil in a large frying pan. Stir fry the asparagus for approx. 5 mins. Add the tomatoes, season, simmer for approx. 5 mins. Stir in the spinach.
Using a tablespoon, make 8 wells in the sauce. Crack the eggs one at a time, slide them carefully into the wells. Cover and leave to solidify for approx. 12 mins., season the eggs with salt.