Warm a skillet or frying pan over medium-heat. Butter both sides of your bread and then grill one side.
Once it has lightly browned, flip bread over to brown other side. Turn the heat to low. Then spread the pesto on the grilled side and the cheese on top.
Allow cheese to melt, then place tomatoes and any other desired toppings on top of the cheese followed by the top piece of bread. Turn the heat off if browning too fast and allow sandwich to sit in the skillet until melted. Slice and serve warm.
Notes
Pesto: I love using my favorite homemade basil pesto when making this recipe. Kirkland is my favorite store-bought Pesto. Additions: A drizzle of balsamic glaze adds a delicious flavor. If I have microgreens, I love adding those too. Protein: Add in sliced cooked chicken (rotisserie chicken works great, sliced turkey or crisp bacon.