Hashbrown Hamburger Pie

1 Pound ground beef
1 Medium onion, chopped
1 Garlic clove, minced
1 (14 1/2 oz) Can diced tomatoes, drained
1 Teaspoon chili powder
1 Teaspoon dried oregano
1/2 Teaspoon salt
1/4 Teaspoon pepper
1 1/2 Cups frozen mixed vegetables
Topping
3 Cups frozen shredded hash brown potatoes, thawed & drained
8 Ounces cheddar cheese, shredded
1 egg
1/8 teaspoon salt
1/8 teaspoon pepper

In a large skillet, cook beef, onion and garlic until beef is no longer pink; drain. Stir in the tomatoes, chili powder, oregano, salt and pepper; bring to a boil. Reduce heat; simmer, uncovered, for 10 minutes. Stir in the vegetables. Pour into a greased 9" pie plate. Combine topping ingredients; spoon evenly over the meat mixture; bake, uncovered, at 400�F for 30 minutes.