Par boil the potatoes until fork tender. I microwaved the potatoes until tender. Drain completely.
Heat oil on medium-high flame in a 10″ cast iron skillet. Add the potatoes along with chili powder, cumin powder, garlic powder, salt & pepper. Gently mix to evenly distribute the spices on the potatoes.
Cook, stirring occasionally until the potatoes are golden brown and crisp all over, should take about 15~10 minutes.
Make Cheese Sauce:
In a skillet, melt the butter and add the flour. Whisk continuously until the mixture is light brown. Stir in the milk and cook stirring until the mixture thickens. Season with cayenne pepper and salt.
Take the skillet off the hat and stir in the grated cheese. Stir until the cheese melts and the sauce is creamy and smooth.
Top the roasted potatoes with the cheese sauce and sour cream. Serve right away and Enjoy!!
Leftover cheese sauce can be refrigerated and heated in a small saucepan until smooth. dd a bit if milk to help in melting, if needed.