Preheat the oven to 375 degrees Fahrenheit.
Take a large skillet and put beef and onion in it. Place the skillet over medium heat and allow the beef to cook well. Make sure the pink shade is gone from the beef pieces, before you drain. Now add in water, sloppy Joe seasoning, tomato sauce and corn, stirring continuously.
Cook the mixture over medium heat and allow the bubbles to form on the top. Right after bubbles start forming, reduce the heat to low and simmer for around 5 minutes, before removing it from the heat and set aside.
Separate the biscuits and flatten them in 3-1/2 inch circles. Take two separate bowls and fill one with milk and the other with cornmeal. Dip the biscuits one by one in each bowl.
Take a 9-inch pie plate and place seven biscuits at the side, with three biscuits in the centre. Press them together, to form crust. Sprinkle the crust with 1/2 cup cheese and spoon the meat mixture over it.
Bake it for around 20 to 25 minutes, until you see the crust turning golden brown. Take remaining cheese and sprinkle over it. Let it cool for around 5 minutes, before serving.