Corned Beef Potato Salad - With meat

1 lb white potato 1/2 teaspoon salt , to taste (corned beef is already salty) 1/2 teaspoon black pepper 2 -3 teaspoons vegetable oil 1/2 cup yellow onion ,[...]

12 ounces leftover cooked corned beef , cut into 1/2 inch cubes 1 lb baking potato , peeled, cut into 1/2 inch cubes 1/2 teaspoon salt 1 tablespoon butter 1[...]

1 (12 ounce) can corned beef , crumbled 1 2/3 cups macaroni (cooked and drained) 1 1/2 cups cheddar cheese , grated 1 1/4 cups milk 1 (10 1/4 ounce) can[...]