Combine seasonings and rub generous amounts into all sides of the roast.
Pour soy sauce onto both sides of roast.
Marinate in the refrigerator if you want, but not necessary.
Add 1/2" of water to crock pot, add marinated roast. Cook on high for 4 hours or on low for 8 hours.
Remove roast and keep warm.
To make gravy, add 1/2 c milk and 1/4 c flour to juices left in crock pot. Whisk to remove lumps and cook on high, whisking periodically, for 20 minutes (make some mashed potatoes and cornbread while you wait.).