Making The Best Pesto Grilled Cheese is straightforward when you follow these simple steps:

1. Prep the Bread: Spread butter on one side of each slice of bread. This will be the outer part that gets crispy when cooked.
2. Assemble: On the unbuttered side of two slices, spread 2 tablespoons of pesto. Layer two slices of cheese on top of the pesto.
3. Add Optional Ingredients: If desired, add sliced tomatoes or a couple of crispy bacon slices on top of the cheese.
4. Top It Off: Place the remaining slices of bread on top, buttered side facing out.
5. Heat the Pan: Heat a skillet over medium heat. Once hot, carefully place one sandwich in the skillet.
6. Cook Until Golden: Cook for about 3-4 minutes, or until the bottom is golden brown. Carefully flip the sandwich and cook the other side for another 3-4 minutes.
7. Check the Cheese: Once both sides are crispy and the cheese is melted, remove the sandwich from the skillet.
8. Repeat: If making more than one sandwich, repeat the process with the remaining ingredients.
9. Slice: Allow to cool slightly, then slice the sandwich diagonally for serving.

Following these steps will result in a deliciously crispy, flavor-packed sandwich!