Grilled Mackerel with Dijon Mustard

If you chance upon a fishing village or a pier where really fresh mackerel can be caught, catch or beguile enough of the fine creatures as will feed your company Clean the guts out and make three deep incisions on either side of the backbone. Salt these wounds well, as well as the interior of the fish. Spread liberally with Dijon mustard and crushed fennel seed if you have some about your perso