Inspired by summer lunches in Maine, this beautiful turkey sandwich comes from the chef Matthew Cahn of Middle Child sandwich shop in Philadelphia. A spiced, savory blueberry jam anchors turkey and cheese on a toasted ciabatta roll. When it comes to this dreamy sandwich, the devil is in the details: Dressing peppery arugula with vinegar, oil and raw grated onion lends yet another layer of flavor that balances the comforting richness of the other ingredients. Store-bought garam masala works…