Baking the tenderloin: Combine all seasonings in a bowl. Rub onto the meat, top, sides, and bottom. Grease the baking pan with butter then put the meat in. You can also put a little bit of water instead of butter. Preheat oven to 350°F. When the temperature is ready, put the pan in the oven. Bake for an hour. After an hour, increase the oven temperature to 375°F and bake for another hour. Pork meat temperature when cooked is 170°.

Making the mashed potato: While the pork is still in the oven, wash the potatoes, peel, and chop. Sprinkle a teaspoon of salt into the water and bring to a boil on high heat. Add the potatoes and cook for about 30 minutes or until tender. Drain. In a deep bowl, mash the potatoes using an electric mixer. Add butter and milk gradually until it's creamy. You don't need to use all the milk.