Taco Potatoes

6 medium potatoes, with or without peels, cooked
1/2 teaspoon salt
1/2 teaspoon chili powder
1/2 teaspoon cumin
1/2 teaspoon paprika
1/2 teaspoon Mexican oregano
1/2 teaspoon garlic powder
1 small onion, diced
1/4 cup butter
Sour cream (for garnish)
Parsley, as garnish

Cut cooked potatoes into bite-size pieces and place in large baking dish. Combine all other ingredients except sour cream and parsley and pour over potatoes. Heat in oven until heated and butter is melted. Serve with sour cream and parsley as garnish.