I used dried Colman's last night, making a rub for the tri-tip I roasted. I mixed equal parts good quality flour (I like King Arthur) and Colman's, then pat it all over the roast, really working it into the flap of fat on top. Some salt and pepper, and roast it in a cast iron skillet on top of a large onion, cut in half. Afterwards, the onion makes for excellent gravy right there in the skillet. It was sensational (as always).
I am a big fan of wholegrain mustard, but I also like a good Dijon.