Preheat oven to 350°F (175°C).
In a large skillet over medium-high heat, add the vegetable oil. Once the oil is hot, place the chicken cubes in the skillet. Sprinkle the chicken with salt and pepper and cook for 3 minutes per side or until golden brown.
Add the flour to the skillet and stir to combine. Cook for another minute, stirring constantly. Slowly pour in the milk and water while stirring continuously until combined. Reduce heat and simmer for 5 minutes or until sauce has thickened.
Add 3 tablespoons of melted butter to the skillet and stir to combine. Pour the chicken and sauce into a 9-inch baking dish.
In a medium bowl, mix together the biscuit ingredients until a soft dough forms. On a lightly floured surface, roll out the dough to ½ inch thick and cut it into 8 biscuits. Place the biscuits on top of the chicken in the baking dish and brush with the remaining 2 tablespoons of melted butter.
Bake for 25 minutes or until golden brown.
Serve warm with your favorite sides.