Grilled Cheese Sandwiches with Sun-Dried Tomato Pesto

In the bowl of a food processor fitted with the steel blade, combine the sun-dried tomatoes with their oil, garlic, salt, red pepper flakes, sugar, basil, pine nuts, Parmigiano-Reggiano and 2 tablespoons of water. Pulse, scraping down the sides as necessary, until the mixture is finely puréed.

Spread one side of each slice of bread with butter, then flip over and spread the pesto evenly over the other side of each slice.

Heat a large nonstick or cast iron pan over medium heat. Place 4 slices of bread, butter-side-down, in the pan. Divide the cheese evenly over the bread, then top the sandwiches with the remaining bread.

Cook until the first side is golden brown, a few minutes. Carefully flip the sandwiches and cook until the cheese is fully melted and the bread is golden brown, a few minutes more.

Let cool slightly, then slice the sandwiches in half and serve.