In a large frying pan, fry the lean mince and mushrooms in oil.
Add the sachet of seasoning mix, 800 ml hot water, and the uncooked pasta contained within the box and bring to the boil.
Reduce heat and simmer for 15 min, stirring occasionally.
Stir in defrosted spinach and simmer for 5 min.
Stir in the crumbled feta.