For breakfast I have a four egg omelette spinach, mushrooms, in order to keep cost down I go to the local supermarket Sunday morning pick up enough eggs for the week, I can normally easily get 2 dozen or more for £2 as they mark them down, as the display dates finish on the Sunday, but use by date is a further week away.
A bag of frozen mushrooms and spinach are 3 for £2 from farm foods, I also get Boursin cheese when it on at 3 for £1 it's a massive £5 for a whole week and there is always mushrooms and spinach left over for other meals. Works out very cheap.