In a large saucepan cover potatoes with water. Boil until fork tender. Drain well
In a large mixing bowl beat potatoes well. Beat in butter, salt and pepper. Add only enough milk to smooth potatoes. Being careful not to add too much. Potatoes should be fairly stiff.
Fold in cheese and set aside.
In a large mixing bowl combine all meatloaf ingredients. Mix well
Divide meat mixture in half.
In a shallow baking dish form a bottom layer
Spread mashed potatoes on top of meat mixture leaving about a 1 inch border
Top with second half of the meat mixture
Gently pat down over potatoes
Pinch edges together all the way around to seal
Cover with foil and bake in a 350° oven for 1 hour
Uncover and drain any excess fat
Return the oven for 20 minutes
Spread remaining mashed potatoes over meatloaf like frosting cake. OR pipe potatoes over meatloaf using a pastry bag
Heat oil in a large skillet to medium heat. Whisk in flour and chili powder. Reduce heat to medium and continue to whisk until lightly browned. Gradually whisk in tomato sauce, chicken broth, cumin, garlic powder, onion salt and salt. Stir until smooth, and continue simmering over medium heat about 10 minutes, or until slightly thickened.
Serve immediately, or keep in a covered bowl in the refrigerator for up to 3 days.