Chicken paired with lobster; veal meatballs braised with cuttlefish; rice dishes that blend shellfish and chicken: these are some of the most classic examples of mar i muntanya, a style of Catalan cooking that blends proteins from the sea and the land. Although a hallmark of Catalan cuisine, these dishes are getting increasingly harder to find, especially in Barcelona. But at La Pubilla, a restaurant in the city’s Gràcia neighborhood, the tradition lives on. Originally opened in 1912, nearly a century later La Pubilla was taken over by chef Alexis…