In a medium skillet, melt 1 tablespoon butter over medium heat. Add sliced peaches and sauté for 3-4 minutes until peaches begin to soften but aren't yet mushy. Lightly salt, reduce heat to low, and add balsamic vinegar. Cook until balsamic vinegar is reduced, then remove from heat.
3 tablespoons butter, 1-2 peaches, kosher salt, 1 tablespoon balsamic vinegar
Top one of the slices of sourdough with ¼ cup of the havarti then top with half of the balsamic peaches. Top with 2 slices of prosciutto, then drizzle with honey and sprinkle with black pepper. Sprinkle with basil then another ¼ cup havarti, then top slice of sourdough. Repeat with remaining sandwich.
4 pieces sourdough bread, 1 cup havarti, 4 pieces prosciutto, honey, black pepper, basil
In a large skillet, melt remaining 2 tablespoons butter over medium heat. Add grilled cheeses, press down lightly, and cook for 3-5 minutes until golden. Flip and continue cooking until cheese is melted and bottom piece is golden. Serve immediately, with additional fresh basil, honey, and flakey sea salt, if desired.
3 tablespoons butter