Preheat a griddle to 400 degrees (or use a nonstick skillet over medium-high heat).
Brush olive oil lightly on one side of each piece of bread. Place bread oil-side down on the griddle.
Layer the slice of cheese on one piece of bread, and the mashed pinto beans on the other side. Place taco turkey meat on beans.
Once cheese has melted and bread toasted, place lettuce and tomato on the turkey, then flip the other piece of bread onto the sandwich so the cheese "seals in" all the other ingredients.