Let’s dive into the process of creating this scrumptious sandwich. Follow these steps for a foolproof meal:

1. Begin by preparing the mayonnaise spread. In a small bowl, mix together the mayonnaise and Dijon mustard. Add a pinch of salt and pepper to taste.
2. Lay out the slices of sourdough bread on a clean surface. Spread a thin layer of the mayonnaise mixture on one side of each slice.
3. On four of the slices, layer two slices of cheddar cheese, followed by several slices of turkey breast and two slices of bacon.
4. Top each sandwich with the remaining slices of bread, mayonnaise side down.
5. In a large skillet, melt the butter over medium heat. Once the butter is bubbling, add the sandwiches to the pan.
6. Cook the sandwiches for about 3-4 minutes on each side, or until the bread is golden brown and the cheese has melted to ooey-gooey perfection.
7. Remove the sandwiches from the skillet and let them cool slightly before cutting them in half.

My tip for a perfectly grilled sandwich? Patience is key. Resist the urge to turn the heat up too high; slow and steady ensures the cheese melts beautifully without burning the bread.