Spinach Pesto Grilled Cheese Sandwich (fromage grille au pesto)

1 Slice the bread into 2 pieces, no more than 1/4 of an inch thick, or it could overwhelm the cheese.2 Butter one side of both slices, then place one of them on the work surface. Make sure that the buttered side is facing down.3 Spread the spinach pesto over the bread and then sprinkle the cheese over the pesto. Then place the remaining slice on top, buttered side facing upwards.4 Heat a large skillet over a medium flame for about 2 minutes. Then place the sandwich on the skillet and cover it. Cook for another 2 minutes until the undersides of the sandwich is golden brown and the cheese has just about begun to melt.5 Uncover the skillet, and turn the sandwich over. Then use a heavy pan or spatula to flatten the sandwich to ensure that the bread remains crisp and not doughy.6 Cook for about a minute until the undersides turn golden brown. Now turn the sandwiches over again and press down with the spatula and cook for 30 seconds more or until the cheese has completely melted. Serve it immediately.