Prime Beef Roast

I recently discovered Save-On Meats at 43 Hastings (no connection to Save-On Foods).   They have a butcher shop and a 50's style diner, very hip, and fun.   All clean and well decorated, you will like it.   We had hamburgers (their own ground beef) and slaw and chips.

The prices are very good and they have grass fed beef and lots of great looking sausages.   In case you don't know, we need to eat animal products from animals that ate grass and other living green plants so that the fat is healthy for us.  

I bought a lovely, very well marbled Save On butchers do not cut off all the lovely healthy fat) grass fed organic prime beef roast.   Contrary to what other butchers have told me, this grass fed beef is not lean at all.   The butcher told me that it depends on the breed.   More investigation and questioning of butchers required. 

Patrick cooked it as follows:

Ingredients:
Beef roast
Salt
Pepper

Instructions:
Take the roast out an hour ahead to bring to room temperature.
Season the outside of the roast with salt and pepper.   
Pre-heat the oven to 350 degrees F.
Put the rack in the middle.
Heat a cast iron frying pan on medium until it's very hot.
Brown the meat on all sides, using large tongs to turn and hold the meat on it's edge.
Put the roast and pan into the oven for about 30 minutes.  
To test for medium rare to rare, .....?