Comfort food never tasted this haute cuisine. The lowly tuna melt goes upscale at Ambrosia Cafe, the eatery created last year in the old Firefly Space by chef Mark Gordon and his partner, John Barocas. They've created a simple yet trendy neighborhood spot complete with landscaped patio and parking outside and Asian-influenced dishes inside. Gordon is reaching high here, and with the ahi tuna salad melt, he displays a particularly good grasp on which ingredients work together -- and how. Ahi chunks mixed with celery and a homemade mayo come piled on a fluffy-centered, crackly-crusted kaiser roll, blanketed with slices of a creamy, nutty Swiss cheese; the cooking has been timed perfectly so that the ahi, which steams a little under the molten cheese, arrives dead-on medium-rare. The sandwich comes with your choice of Ambrosia's fabulous fries or a side of steamed vegetables. Either way, your meal should go swimmingly.