Braised Pork Belly Sandwich with Pesto Mayo

Name: Braised Pork Belly Sandwich with Pesto Mayo
Ingredients: 4 (8-ounce) square portions pork belly; Kosher salt; Freshly ground black pepper; Grapeseed oil, to coat bottom of pan; 4 whole cloves garlic; 1 onion, diced; 1/4 cup brown sugar; 1/4 cup balsamic vinegar; 2 tablespoons Dijon mustard; 1 sprig rosemary; 1/4 cup dry portobello mushrooms; 2 Scotch bonnet peppers or jalapenos, optional; 2 cups beef broth; 2 cups chicken broth; 4 small ciabatta rolls, split and toasted; 8 ounces smoked mozzarella, sliced; 1/2 cup prepared pesto; 1/2 cup mayonnaise; Dash lemon juice; Pinch kosher salt; Pinch freshly ground black pepper