Lay bacon slices in a single layer in a large skillet. Fry over medium heat until starting to brown. Fry on both sides. Remove from the pan, but save the grease.

Add butter to the skillet and melt. Crack eggs into the pan, being careful not to break the yolks. Place tomato slices, mushrooms, and bread into the skillet, keeping everything separate. Fry gently, stirring mushrooms and tomatoes occasionally. Flip bread to brown on both sides.

When egg whites are set but the yolks are still runny, dish half of everything onto each of two warmed plates and serve immediately.