I use Paprika, Garlic Powder, Onion Powder, Brown Sugar, Kosher Salt and Pepper. I do not use Mustard; I use Honey to make the glue for all these spices. That made for a much better tasting Pork roast.
I did a pork roast, started out I wanted to do it my pressure cooker, but that is another story. It was no go. But to start, I put some salt, pepper and Italian Seasoning on the roast, and then browned all sides in a little olive oil. It then went in the Pressure cooker, had problems, off to oven it went. Let me tell you that was the very best pork roast I have ever had. I plan on putting together a rub using Italian seasoning this year