The scent of lighter fluid has lost its thrill. Diehard carnivores yawn at the mention of burgers. And the sight of potato salad inspires a vague despair. Welcome to the mid-summer barbecue slump. Before you give up on your grill, stop in at Dirk’s Fish and Gourmet Shop, where twenty kinds of fresh fish are flown in daily. They’ve got your everyday gills — halibut, swordfish, Dungeness crabs, sea scallops, four different kinds of salmon — but Dirk’s real hook is the rare and exotic. Give them notice, and they can supply whatever strange creature of the deep you can dream up (hamachi or snook, to name a couple). They’ll even cut and bone to your specifications. Show up on Saturdays between noon and 3 p.m. for a grilling demonstration and tasting and you’ll be cooking like a professional fishmonger in no time. (Admittedly, a somewhat limited ambition.) But enough to keep your guests — and your grill — fired up for at least another six weeks. Dirk’s Fish and Gourmet Shop, 2070 North Clybourn Avenue, between Fullerton and Armitage Avenues (773-404-3475).