Preheat oven to 350°F (175°C).

Cook hot sausage and drain grease.

In a large bowl, combine corn meal, milk, eggs, soda, salt, and garlic powder.

Add chopped onion, grated cheese, whole kernel corn, and mashed Ro-Tel tomatoes and green chilies to the bowl.

Stir in the cooked and drained sausage.

Grease a 9 x 12-inch baking pan generously.

Pour the cornbread mixture into the prepared pan.

Bake for one hour, or until a toothpick inserted into the center comes out clean.

Let cool slightly before cutting into squares and serving.