If you love po-boys, you already know how you like them. It’s sloppy roast beef or crispy shrimp, thin-sliced ham or fat fried oysters. I bet you even have a precise combination for how you like it dressed. Just listen to some po-boy pros when they order at the counter. In their confident cadence and specifics, they can sound like surgeons gloved up for an operation. “Hot sausage. Dressed. No lettuce.”