Cajun Prime Rib - cooking recipe

Ingredients

4 lbs prime rib roast
1/4 cup black pepper
1/4 cup garlic powder
1/4 cup salt
2 onions, thinly sliced
1 tablespoon salt, plus
1 teaspoon salt
1 tablespoon white pepper, plus
2 teaspoons white pepper
1 tablespoon fennel seed, plus
2 teaspoons fennel seeds
1 tablespoon black pepper, plus
3/4 teaspoon black pepper
2 1/2 teaspoons dry mustard
2 1/2 teaspoons cayenne pepper

Preparation

Remove fat cap off top of meat (butcher can do this for you) and save.
Place the roast, standing on the rib bones, in a very large roasting pan.
Then with a knife make several dozen punctures through the silver skin so seasoning can permeate meat.
Pour a very generous, even layer of 1/4 c black pepper over the top of the meat (the pepper should completely cover it); repeat with the 1/4 c garlic powder, then the 1/4 c salt, totally covering the preceding layer.
Carefully arrange the onions in an even layer on top so as not to knock off the seasoning.
Place the fat cap back on top.
Refrigerate 24 hours.
Bake ribs in a 550F oven until the fat is dark brown and crispy on top, about 35 minutes.
Remove from oven and cool slightly.
Refrigerate until well chilled, about 3 hours. (this is done so the juices will solidify and the steaks can be cooked rare.) Remove fat cap and disgard.
With the blade of a large knife, scrape off the onions and as much of the seasonings as possible and discard.
Then with a long knife, slice between ribs into 6 steaks (4 will have bones); trim the cooked surface of meat from the 2 pieces that were on the outside of the roast.
Season and cook in your favorite way for steaks.
TO BLACKEN THE STEAKS: Combine the remaining ingredients (1 T + 1 t salt through cayenne pepper) thoroughly in a small bowl; you will have about 8 tablespoons.
Sprinkle the steaks generously and evenly on both sides with the mix.
Use about 4 teaspoons on each steak and press it in with your hands.
Heat a cast iron skillet over very high heat until it is beyond the smoking stage and you see white ash on the skillet bottom--at least 10 minutes. (The skillet cannot be too hot for this method.) Place one steak in the hot skillet (cook only one side at a time) and cook over a very high heat until the underside starts to develop a heavy, black crust, about 2 to 3 minutes.
Turn the steak over and cook until the underside is crusted like the first, about 2 to 3 minutes more.
Repeat with the remaining steaks.
Serve each steak while piping hot.