I bought 2.
The tri-tip cut has a pretty good layer of fat on one side. I like to leave most of it on as it contributes to the taste and juiceness of the meat. If it's really thick I'll trim it down a bit.
On top of that fat there is usually a membrane that should be cut away. If it's left on it can get pretty chewy. Trimming away the membrane also gives an easy opportunity to take of some excess fat.
There are lots of ways to cook tri-tip. One of the most popular is on the barbecue. In fact, Santa Maria Tri-Tip (this is just one recipe, Google will show you dozens more) is one of the absolute best barbecue meals you'll ever have. If you ever get the chance to have that at a county fair, carnival, flea market, etc., take it! Your taste buds will be doing somersaults.
But, I don't always feel like starting the barbecue grill. Sometimes I just want to throw the roast in the oven and not do a lot of fussing.
For those times I drag out that faithful cast iron frying pan, pop the roast into it, coat both sides generously with a good seasoning like Lindberg-Snyder Porterhouse and Roast Seasoning, and get it into the oven.
About 40-45 minutes later...
Dang it, I'm drooling. Gotta go get some leftovers... thanks for reading.