01 - 
                Preheat the oven to 350°F and grease a 13x9-inch baking dish.
              
              
              
                02 - 
                Sauté the meat and onion in a skillet until the meat is cooked through.
              
              
              
                03 - 
                Meanwhile, peel the potatoes and cut them into ¼-inch slices.
              
              
              
                04 - 
                Arrange a layer of potatoes on the bottom of the prepared baking dish. Grind some salt and pepper over them.
              
              
              
                05 - 
                Add about a third of the beef mixture and spread it evenly over the potato layer.
              
              
              
                06 - 
                Add a third of the cheese, then repeat these layers again twice, ending with a cheese layer.
              
              
              
                07 - 
                Stir both milks with the soup and add salt and black pepper if needed.
              
              
              
                08 - 
                Pour this mixture over the top of the casserole.
              
              
              
                09 - 
                Cover with foil and bake for an hour.
              
              
              
                10 - 
                Discard the foil and give it another 15 minutes in the oven to brown the cheese.
              
              
              
                11 - 
                Serve hot.