Preheat oven to 250 degrees.
Get a pan big enough to fit the whole roast and heat oil over medium flame in it. Pour in all the spices and mix well.
When the oil is sufficiently heated up, put in the roast and cook for about 6 minutes on each side.
Set up the roast on rack in a way that it won't marinate in it's own juice while it roasts and get soggy. Put it in the oven on 250 for 4 hours.