1Peel , cut and boil the potatoes , add salt to the boiling water.
Strain , mashed roughly , add milk , sour cream and parmesan cheese. Mashed until smooth.
2In a big pan , heat olive oil and butter together.
Once butter melts and start bubbling , add the onions , cook until golden brown.
Add the meat , brown it , add salt and pepper to taste , cumin and paprika. Set aside
3Butter a baking dish ( 3 qts. ) , place a small amount of potatoes to cover the bottom , top with the meat ( with all the juices from the pan ) , and top with rest of the mashed potatoes
4Preheat oven to 400 F.
With a fork , you can make a big X and place a bit of butter on each end and center.
Sprinkle with parmesan cheese.
Put in the oven for 20' aprox. , or until butter melts and cheese is golden and bubbly ( you can switch to broil for 1 or 2 minutes).
Serve warm , and enjoy !!