I must admit, I was quite the skeptic when my husband told me about this recipe. Since we got our new grill, he has been reading grill forums and recipes to come up with delicious meals and cooking methods. Several sources, such as this one, recommend rubbing your meat with yellow mustard and then a rub. Appartently the mustard holds in the juice and helps the spices stick to the meat. I thought the mustard flavor would be overwhelming but it isn't and the results were awesome!! The first time he made these, he just made his patties with the mustard and rub. I wanted to steal his burger! So, this past weekend he made them all the same and I don't remember the last time I have enjoyed a burger as much.