The Boston restaurant scene is overrun with aspiring chefs inventing new dishes and putting a creative spin on old ones. For the Roadfood traveler who wants to taste the abiding flavor of the city, things to eat include Indian pudding and baked beans, artisan ice cream at Toscanini’s, Rancatore’s, and Christina’s, Boston cream pie and Parker House rolls (still specialties at Parker’s Restaurant in the Omni Parker House), sponge cake with buttercream frosting at Lyndell’s Bakery, Santarpio’s pizza and charcoal-cooked sausage, and a burger at Mr. Bartley’s