Preheat oven to 350°F (180°C). In a large mixing bowl, combine ground Pork, onion, breadcrumbs, milk, apples, parsley, mustard, sage, egg, salt and pepper, being careful not to overmix. Place in a greased medium loaf pan. Place pan on a baking sheet and bake for about 90 minutes, or until the middle of the meatloaf registers 160°F (60°C) on a meat thermometer.

Sauce: In a small saucepan, melt butter, then add onions over high heat. Cook onions until browned. Away from heat, stir in flour until fully incorporated. Return to heat and whisk in bouillon. Bring to a boil and adjust seasoning. Simmer for about 5 minutes.