Heat a non-stick skillet or frying pan over medium heat and add olive oil or butter.
Allow it to melt and coat the pan evenly.Crack the eggs into the pan, making sure to keep the yolks intact.
Season with a pinch of salt and pepper. Let the eggs cook for about 2-3 minutes until the whites are set but the yolks are still slightly runny. If you prefer your eggs fully cooked, you can cook them longer to your desired doneness. To get them completely done - pop the yolk in the beginning.
Once it is done, add the cheese on top to melt.While the eggs are cooking, lightly toast the bread slices either in a toaster or on a separate pan until they reach a golden-brown color and crisp texture.
Once the bread is toasted, remove it from the heat and assemble the sandwich. Put the mayonaisse on the bread. Add the bacon (if using). Place the tomato slices on one slice of bread.
Carefully slide the fried eggs onto the tomato slices. If desired, you can layer additional toppings.
Finally, top the sandwich with the remaining slice of bread. Press gently to hold everything together. Slice the sandwich diagonally or in half, depending on your preference, and serve immediately. Enjoy the delicious combination of flavors and textures in each bite!