Mix all the ingredients and form the 1 1/2 inch meatballs. Arrange them on one side of the pan covered with baking paper. Cut the larger mushrooms in pieces and the smaller ones leave in one piece. Cut the potatoes in cubes. Season the mushrooms and potatoes, spread them on the other side of the pan covered with baking paper and spray with oil. Bake for 20 minutes on 425 F degrees.