I've tried several different things, from store bought marinades and steak rubs to salt crusts I found on the egghead forum. My favorite is plain jane kosher salt, fresh ground black pepper, minced garlic and onion powder. Combine all those ingredients, rub the roast down with olive oil and then liberally coat with your mixture. Seal it up with plastic wrap and let it sit in the fridge 8-10hrs. Pull it out a couple hours before you cook and let it come to room temp.

I have found the reverse sear works best to my liking. Low and slow around 250ish til internal temp in the middle of the roast is about 125. Then crank up the heat to create that outside crust. That is the part you gotta play by ear. Hard to beat when served with some good horseradish!