Combine turkey scallops in a mixing bowl with oil, salt and pepper. Heat the grill or dry cast-iron pan over high heat until smoking. Sear the turkey slices about 1 minute per side. Transfer to a cutting board. Chop into 1/2 inch strips and reserve in a bowl with the juices from the board.
To make tacos, toast the tortillas. For each serving, stack 2 tortillas and spread with a layer of black beans. Top with seared turkey strips, a tablespoon each of salsa and pickled shallots, and avocado slices. Roll and serve hot.