2 pounds ground beef

¼ medium onion, finely chopped

1 ¼ cups shredded Cheddar cheese, divided

½ cup sour cream

1 tablespoon dried parsley

1 tablespoon taco seasoning

1 teaspoon dried oregano

½ teaspoon ground black pepper

2 ½ cups enchilada sauce

1 ½ teaspoons chili powder

1 clove garlic, minced

½ teaspoon salt

8 flour tortillas

1 (15 ounce) can black beans, rinsed and drained

1 (4 ounce) can sliced black olives, drained