Bacon and Egg Lyonnaise Sandwich

Name: Bacon and Egg Lyonnaise Sandwich
Ingredients: 4 slices thick-cut bacon, cut into ½-inch pieces; 3 tablespoons red wine vinegar; 1 teaspoon Dijon mustard; 1 teaspoon honey; ½ teaspoon kosher salt, plus more; 1 tablespoon unsalted butter, plus more for buns; 4 brioche buns; 4 large eggs; Freshly ground black pepper; 2 small heads of frisée; ⅓ cup crumbled Gorgonzola