Simple but amazing oven roasted top sirloin

I grabbed a large top sirloin at the market the other day -- it was dirt cheap and a good looking cut:

I roasted this sucker up -- it was easy and produced a great roast beef that we served for guests this weekend -- it served five very hungry people and we still have enough for days of sandwiches.

There were several tricks to making this roast come out beautifully.

1.  The Au Jus.

I started the Au Jus a day ahead of time.  It's not much work but requires a long slow boil.  I used leftover New York Strip from the other day (mostly bones and trimmings).  I placed a strainer inside a very large pot, filled with water, the steak trimmings, onions, bay leaves and some old parsley.  I then boiled it for about 24 hours, constantly adding water to keep it covered.  I also added a touch of beef bouillon (not much, because it adds salt and possibly MSG).

Several hours before beginning the roast, I removed the strainer so that all that was left is a rich but watery brown liquid.  (You could omit the strainer and just strain into another pot at this point).  At this point the mixture was about 1/2 gallon.

Now -- Under careful monitoring the heat was turned up until the liquid reduced by 50% (to about a quart) to concentrate the flavor.

Later on, I did a little bit of back-and-forth -- Some of the Au Jus was used to baste the roast and to make my "mop" but the liquid in the roasting pan made its way back into the Au Jus for extra flavor.

2.  Searing & preparation for oven roasting

This makes the roast!  Heat a large skillet or heavy roasting pan on medium heat.  Lightly rub oil over the surface of your roast.  Get your hands dirty!  Now drop that sucker into the hot skillet or pan and brown each side so it looks like this:

Remove, let cool and then make small slits into which you should insert slivered garlic.  Slice an onion or two and place in the bottom of the pan, setting the roast on top, fatty side up.

3.  Roast at 200 to 300 degrees until the temperature (get a meat thermometer!) inside is at least 125 degrees.  I cooked to 135 for a medium-rare to medium roast.  Remember that the internal temperature will continue to increase for a few minutes after you stop cooking.  For truly savory juiciness, baste every 15 minutes.  It's best to start with some of the Au Jus.

4.  When done, transfer the drippings back to the Au Jus.

5.  Slice and enjoy!

More detailed cooking instructions here.