Crab Cakes with Mustard Sauce

I’ve eaten crab cakes at Obrycki’s in Baltimore, Harris Crab House in Grasonville, Maryland, King Neptune’s in Gulf Shores, Alabama, The Wreck in Mount Pleasant, South Carolina, and dozens of other celebrated Southern crab houses, but the only ones that could touch Louis Osteen’s small wonders at his restaurant on Pawleys Island, South Carolina (made today with both crab and lobster) were the simple cakes served at Jimmy Cantler’s Riverside Inn in Annapolis, Maryland. “Just