Add ground beef to large, non-stick skillet over medium heat; season with Adobo and chili powder. Cook, breaking up meat with wooden spoon, until well browned, about 5 minutes; drain and discard fat. Stir in pinto beans in sauce and 1 cup drained pico de gallo; bring bean mixture to boil. Simmer, stirring occasionally, until bean mixture thickens, about 5 minutes.
Remove skillet from heat; top with 1 cup cheese and scallions; let sit until cheese melts, about 2 minutes. Top with shredded lettuce, remaining pico de gallo and remaining cheese. Serve with warm flour tortillas and sour cream, if desired.