by ALICE T. CARTER,  Tribune-Review Theater Critic.... It's hard to believe that it took this long for a restaurant to open at Sixth and Penn, which is arguably the crossroads of the Pittsburgh Cultural District. That Six Penn Kitchen finally did last fall is cause for celebration. This is a restaurant that prides itself on smoking its meats on site. All desserts -- even ice cream -- are created in the kitchen. Vegetables are fresh, not frozen. Menu items change regularly, a sign that someone in the kitchen has an enthusiasm for food and its possibilities. An upscale division of Eat 'N' Park Hospitality Group, it's both welcoming and sophisticated with a menu organized around some familiar comfort foods transformed by imaginative culinary upgrades. READ MORE OF THIS ARTICLE ON THE PITTSBURGH TRIBUNE-REVIEW WEBSITE: http://www.pittsburghlive.com/x/pittsburghtrib/s_428835.html