Brisket Sandwich

Name: Brisket Sandwich
Ingredients: 1 (6 to 7-pound) first-cut brisket; 1 head garlic, peeled and thinly sliced; 20 peeled and very thinly sliced fresh ginger; 6 shallots, thinly sliced; 2 onions, thinly sliced; 1/4 cup brown sugar; 2 teaspoons kosher salt; 1 teaspoon freshly ground black pepper; 1 onion, peeled and chopped; 1 chipotle pepper, in adobo sauce, chopped; 1 clove garlic, minced; 1 cup apple sauce; 1 cup ketchup; 1/2 cup honey; 1/4 cup molasses; 1/4 cup soy sauce; 1 tablespoon Worcestershire sauce; Juice of 1 lemon; Salt and freshly ground black pepper; 8 onion buns, lightly toasted; Tomato slices, for garnish; Lettuce, for garnish; Deep-fried onion rings, for garnish