Juicy Roast Beef - cooking recipe

Ingredients

3 3 lbs sirloin tip roast or 3 lbs eye of round roast (approx.)
1 1/2 tablespoons vegetable oil
1/2 medium onion, in 1/8 inch sclices
pepper (optional)

Preparation

Pre-heat oven to very hot, 500 degrees F.
Prepare 8x8 baking pan with non-stick spray.
Remove excess fat from roast, pat dry with paper towel, and place in pan.
Rub pepper on the roast if desired.
Liberally rub or brush with oil.
Arrange onion slices to cover the bottom of the pan around the roast.
(Note the \"grain\" of the roast before cooking since it will seem more tender if carved against, or perpendicular to, the grain rather than parallel with the grain.)
Place in hot oven, uncovered--note that the times below are from this point.
After 5-10 minutes lower oven setting to 350F; let the oven cool gradually without opening door After 35-40 minutes, pour about 1/2 cup hot water over the onions; make a foil tent to cover the brownest parts of the roast, spraying first with non-stick spray, and return to oven.
Add 1/2 cup hot water at 15-20 minute intervals or whenever the bottom becomes dry and cook to desired level of doneness: Approx.
1 hr (20 mi. per lb.) for rare (125-130F); 1 1/4 hr (25mi. per lb.) medium rare (135-140F); 1 1/2 hr (30 mi. per lb.) medium (145-150F); 1 3/4 hr (35 mi. per lb.) medium well (155-160F).
Important: Allow the roast to\"rest\" at room temperature for at least 15 minutes before carving
Transfer roast to serving platter, and pour another 1/2 cup of hot water over the drippings (assuming they're fairly dry), stir, strain out the onions, and pour over the roast.