Cooking over an open fire in restaurant kitchens has been big this past year, so it’s only logical that letting diners grill their own food would be the next step. Of course, Korean barbecue joints have been doing this for years, so the concept is hardly new. But while Chicago doesn’t lack for Korean barbecue, Logan Square did until November, when Ryuu Asian BBQ opened its doors. The sleek new spot doesn’t limit itself to Korean fare, or even to Asian barbecue: the menu also includes sushi, Thai noodle and rice dishes, and a few Vietnamese, Laotian, and Malaysian entrees.