Start by preheating the oven to 400 degrees.
Then prepare a 9×9 casserole baking sheet and clean with a non-stick cooking spray.
In a bowl put the mashed potatoes, parsley, thyme, and oregano. After that season with salt and pepper, stir until well mixed.
In a hot frying pan sauté the onion, add the ground meat, salt, pepper, paprika, and hot red pepper.
Then, add the gravy to stir until it thickens.
Put the peas, the diced carrots, and the shelled corn. Stir then turn off the stove.
In a bottom layer, casserole baking dish put 1/2 of the seasoned mashed potatoes, flattening using a plastic spatula.
Then put the stir-fry of ground meat and vegetables in the second layer.
For the last layer put the remaining ground potatoes on top and sprinkle with the diced butter.
Put a casserole baking sheet in the oven and bake for 30 minutes or until the potatoes are browned.