Preheat the oven to 375 degrees. In a large bowl combine the ground beef, ground pork, breadcrumbs, egg, milk, 2 tablespoons Cajun seasoning, half the diced onion, half the diced bell pepper, and the minced garlic. Mix until evenly blended but do not overwork the meat. Shape into a loaf and place in a loaf pan. Bake for 50 to 55 minutes until the internal temperature reaches 160 degrees.