In large skillet over medium-high heat, add the cooking oil, and when it's hot, add the liver pieces and cook until just browned.
Remove pieces with slotted spoon.
Add the green bell pepper, celery, and onion to hot skillet and cook until softened slightly; reduce heat to low.
Return liver to skillet and add crushed tomatoes, basil, salt, pepper, and garlic powder, stir, cover skillet and simmer gently for 25 to 30 minutes.
Stir in rice and serve.