Cut green pepper in half lengthwise; remove core and seeds.
Place peppers, hollow-side-up, in a shallow, heat-resistant, non-metallic baking dish.
In a medium-sized bowl, crumble beef.
Add rice, salt, pepper, oregano, garlic powder, water, egg and 1/2 cup of tomato sauce. Mix until thoroughly combined.
Spoon mixture into pepper halves.
Spoon remaining tomato sauce over peppers.
Heat, covered loosely with wax paper, 14 minutes in Micro- wave Oven or until meat is cooked and peppers are as tender as desired.
Allow to stand 4 minutes, covered, before serving.