4 Make sauce
Once soft, add the garlic powder and flour and cook, stirring, for 1 min until a sandy paste forms. Once a paste has formed, whisk in the milk and cook for 3-5 min further or until the sauce has thickened. Add the measured water (use the pasta water), stock cube, oregano, mozzarella, spinach and Worcestershire sauce. Cook for 1 final min and season with pepper.