1 medium onion, chopped
4 tablespoons vegetable oil
2 garlic cloves, finely chopped
1 pound ground beef chuck
1 teaspoon sugar
1/2 teaspoon ground cinnamon
1/2 teaspoon cayenne
1/4 teaspoon ground allspice
1/4 teaspoon black pepper
3/4 teaspoon ground ginger
1 1/4 teaspoons salt
1 (14- to 15-ounce) can diced tomatoes in juice
2/3 cup yellow cornmeal
1/3 cup all-purpose flour
1 teaspoon baking powder
1/3 cup whole milk
1 large egg
2 ounces coarsely grated sharp Cheddar (1/2 cup plus 2 tablespoons)