There's a bad recipe?
HERBS AND SPICES SALAD DRESSING OR ZESTY ITALIAN WITH 2CHOPPED GARLIC CLOVES.PUT IN A ZIP LOCK IN THE FRIDGE OVER NIGHT THEN WRAP IN TIN FOIL AND B.Q. WITH THE B,Q, ON LOW WITH THE LOIN ON THE SIDE THAT IS OFF. FOR A COUPLE OF HOURS WHENS DINNER?

I'm salivating..........

I assume you mean backstraps, not the real tenderloin, which is inside the cavity, up against the spine? If so, my best recipe for backstraps is this. I take one whole side, trim any fat and silverskin from it, then cut it into three equal length "logs". Now sprinkle with grated onion and some garlic powder and a little black pepper and place, then tie all three together with twine to make one log or roast. Place some pork fat or uncured bacon on top as "larding". Roast in a 325 degree over until just medium rare (about 130 degrees on a meat thermometer). Slice thinly with an electric knife and serve with brown gravy and sauteed mushrooms. This is as good as any "prime rib" you ever ate!
-Jim