**Prepare the Ingredients**
Cook the bacon in a skillet until crispy and set aside. If you’re using a different protein, cook it as desired. Fry the egg in a small frying pan to your preferred doneness (sunny-side-up or over-easy works great). Season the egg with a pinch of salt and pepper.
**Assemble the Sandwich**
Butter one side of each slice of bread. On the unbuttered side, layer one slice of cheese, followed by the cooked bacon (or protein), and then the fried egg. Top with the second slice of cheese and close the sandwich with the buttered sides facing out.
**Grill the Sandwich**
Heat a skillet or frying pan over medium heat. Place the sandwich in the pan and grill for 3-4 minutes on each side, pressing gently with a spatula, until the bread is golden brown and the cheese is melted.
**Serve**
Once the sandwich is grilled to perfection, remove it from the pan and slice in half. Serve immediately while hot, and enjoy with a side of fresh fruit, hashbrowns, or a salad for a complete breakfast.