In a large bowl combine flour, onion powder, garlic powder, salt and pepper.
Dredge sirloin pieces lightly in flour mixture.
In a large skillet heat oil over medium-high heat.
Brown beef in batches, until browned on all sides.
Remove to a paper towel lined plate.
When all beef is browned, add to Crock Pot.
In a small bowl combine soup, onion soup mix, beef broth and Worcestershire.
Mix well. Pour over beef.
Add water, bouillon cube, salt and pepper to taste.
Stir well.
Cook on LOW 6-8 hours until gravy has thickened a bit and beef is cooked through.
Serve over cooked egg noodles, rice or mashed potatoes.
Garnish with parsley if desired.