Preheat the oven to 300°F (150°C). In a large Dutch oven, heat olive oil over medium-high heat. Season the short ribs with salt and pepper, then sear them in the pot until browned on all sides. Remove the ribs and set aside.

In the same pot, add chopped onion, carrots, and celery. Sauté until softened, about 5 minutes. Add minced garlic and cook for another minute.

Stir in the beef broth, red wine (if using), tomato paste, thyme, and rosemary. Bring to a simmer. Return the short ribs to the pot, cover, and transfer to the oven. Braise for 3 hours until the meat is tender and falling off the bone.

For the Fried Salmon Bites, heat oil in a deep skillet or fryer to 350°F (175°C). Set up a breading station with three bowls: one with flour, one with beaten eggs, and one with breadcrumbs mixed with salt and pepper.

Dredge each piece of salmon in flour, dip in the egg, then coat with breadcrumbs. Fry the salmon bites in batches until golden brown and cooked through, about 3-4 minutes. Drain on paper towels.

For the Creamy Macaroni and Cheese, cook the elbow macaroni according to package instructions until al dente. Drain and set aside.

In a large saucepan, melt butter over medium heat. Stir in flour and cook for 1-2 minutes until lightly golden. Gradually whisk in the milk, cooking until thickened, about 5-7 minutes.

Stir in cheddar and Parmesan cheese, mixing until melted and smooth. Season with salt, pepper, and mustard powder if using. Add the cooked macaroni to the cheese sauce, stirring to combine.

To assemble the dish, serve a generous portion of creamy macaroni and cheese on each plate. Top with braised beef short ribs and a few fried salmon bites.