Heat oven to 450°F.
Drizzle potatoes with EVOO, seasoning blend or salt and pepper. Arrange potatoes on baking sheet. Bake 40-45 minutes, turning pan and flipping potatoes over halfway though cooking time.
Heat a medium pot over medium to medium-high heat. Melt butter, whisk in flour and cook 30 seconds to 1 minute. Whisk in mustard, Worcestershire and stock. Let gravy thicken a couple of minutes so it coats the back of a spoon. Pour into small individual cups and serve with fries alongside for dipping.