Steps:

• Heat shredded pork according to package directions. Stir in garlic. Layer 4 slices of bread with cheese, onion, pork mixture and remaining bread. Spread outsides of sandwiches with mayonnaise., In a large nonstick skillet, toast sandwiches in batches over medium-low heat until golden brown and cheese is melted, 2-3 minutes per side.

Steps:

• Preheat oven to 350°F. Coat a 13- x 9-inch baking dish with cooking spray; place on a baking sheet lined with aluminum foil, and set aside. Fill a large pot with salted water, and bring to a boil over high. Add pasta, and cook according to package directions. Drain.
• While pasta cooks, melt 6 tablespoons of the butter in a large saucepan over medium. Add onion; cook, stirring often, until just tender, about 5 minutes. Stir in flour; cook, stirring constantly, until onion is coated in flour, about 1 minute. Gradually whisk in milk, mustard, garlic powder, and black pepper; cook, stirring constantly, until mixture thickens slightly, about 10 minutes. Remove from heat. Gradually stir in Cheddar and Colby-Jack cheeses in ¾-cup increments until melted and smooth, about 2 minutes.
• Stir pork and drained pasta into cheese mixture in saucepan. Spoon into prepared baking dish. Microwave remaining 2 tablespoons butter in a small microwavable bowl on HIGH until melted, about 30 seconds. Stir in panko until combined. Sprinkle evenly over pasta mixture in baking dish.
• Bake in preheated oven until browned and bubbly, about 30 minutes. Remove from oven; let stand 10 minutes. Sprinkle with scallions. Spoon evenly onto serving plates; drizzle with barbecue sauce, and serve.