Chop onion, celery, and bell pepper into small, uniform pieces.
Heat large skillet over medium heat and add canola oil.
Add chopped onion, celery, and bell pepper to the skillet. Cook until tender but not brown.
Add ground beef to the skillet, breaking it into small pieces with a spatula. Cook until beef is completely browned.
Blenderize the stewed tomatoes until smooth and add to the beef mixture.
Add chili powder and water to the skillet. Mix thoroughly to combine all ingredients.
Reduce heat to low, cover and simmer for several hours, stirring occasionally.