In a medium frying pan, gently fry the hash browns in butter and setaside. Fry the bacon until crisp in the same pan and remove. Add the mushroomsand fry on both sides and set aside.
Now assemble. On a greased baking tray lay out the hash browns and topwith 2 rashers of bacon. Place mushroom and then the bacon on top, cover with aslice of cheese and finish with a slice of tomato.
Place in oven till cheese melts. Serve with toast and streaky bacon.