In 10-inch skillet over medium-high heat, in 2 tablespoons hot salad oil, cook turkey thigh until well browned. Add 1/2 cup water; heat to boiling. Reduce heat to low; cover and simmer 2-1/2 hours, until turkey is fork-tender, adding more water if needed.
Remove turkey from skillet; cool slightly until easy to handle. Remove meat from bones: cut meat in 1/2-inch pieces. (Refrigerate broth for use in soup another day.)
In 3-quart saucepan over medium heat, in 2 tablespoons hot salad oil, cook onion and celery until tender, about 5 minutes, stirring occasionally. Add turkey, tomatoes and their liquid, kidney beans and their liquid, chili powder, salt and pepper; heat to boiling, stirring occasionally.
Spoon hot turkey mixture into 2-quart casserole Preheat oven to 400°F.
Meanwhile, prepare Tamale Topping: In medium bowl with fork, combine cornmeal, flour, baking powder, salt and sage.
In small bowl with fork, stir together egg, milk and salad oil until well mixed; stir into flour mixture just until batter is mixed.
Pour batter over hot turkey mixture in casserole; bake 20 minutes or until toothpick inserted in center of Tamale Topping comes out clean. Serve piping hot at table in casserole.